>> plus, the heroes, stories of bravery from inside the school, including the young teacher who promised her first graders they'd live to see christmas. >> i wanted them to know that somebody loved them and that to be one of the last things they heard. not the gunfire in the hallway. it's so horrible. >> and the shooter, a 20-year-old armed with an assault rifle and two handguns. his mother among the dead. the latest breaking details on who he is and why he did it. >> announcer: from the global resources of abc news, with terry moran and bill weir in new york city and cynthia mcfadden in newtown, connecticut, this is a special edition of "nightline," tragedy at elementary school. good evening. i'm cynthia mcfadden. tonight we join you from a community just beginning to process a great tragedy that unfolded here this morning.

a little while ago i was just down the street where a thousand people gathered inside and outside saint rose catholic church here in newtown, connecticut, to mourn the loss of 26 people, including 20 schoolchildren, most between the ages of 5 and between years old, shot and killed in their elementary school classrooms this morning. schools in this town are part of the draw for people who live here with some of the highest test scores in the state. the kind of place parents move for the sake of their children. abc's dan harris has been at the scene since early today. dan? >> reporter: cynthia, good evening. it all started a little way behind the volunteer fire department, down the road at a suburban elementary school which tonight is in the history books for the worst of all possible reasons. and this town, which one parent today described as the safest place in america, is in total shock. 90 minutes into the school day on a bright winter morning here, police got a call from the sandy

hook elementary school. >> sandy hook school, caller's indicating she thinks there's someone shooting in the building. >> reporter: at around 9:30, the shooter, 20-year-old adam lanza, a former student in the local schools, shown here as a teenager, had barged in. according to the police, he was heavily armed, coated in body armor, and ready to kill. >> we heard this racket at our classroom and we were like all scared, so then we heard them say, go in your cubbies. >> reporter: there were more than 600 children from kindergarten through fourth grade inside. >> it was really scary. teachers just said, sit down inside the corner and be quiet. >> reporter: calls went out to police even as shots were still being fired and within five to ten minutes, tactical teams with long guns drawn swarmed the school, a stark contrast against the backdrop of this bucolic, woodsy neighborhood.

>> reports that the teachers saw two runners past the building which would the rear of the building. >> i need units in the school, i got bodies here. >> reporter: petrified students and teachers looked for safe places to hide. one teacher locking her children in a bathroom as police combed the building looking for the shooter. >> newtown police immediately upon arrival entered the school and began a complete active shooter search of the building. that included checking every door, every crack, every crevice, every portion of that school. >> we heard screaming. and then the police came in. and he's like, is he in here? then he ran out. >> reporter: 8-year-old alexis was in her third grade classroom at the time. >> you hear an ambulance and police officer come and everybody was a little scared, crying. i felt actually a little sick. and i thought i was going to throw up. >> reporter: were kids crying and screaming? >> yeah, kids were crying. not screaming. they were all huddling together.

and they got -- they felt so sick. >> reporter: teachers led the students single file from the schoolhouse to a nearby fire station. >> we got in a line. we had to close our eyes. and we all put our hands on other people's shoulders. and then our teacher held the first person's hand and she led us out. >> reporter: parents were alerted by text message in a frantic parade of them arrived at the fire station hoping to find their children alive. >> heartbreaking. it's heartbreaking. i mean, i don't -- when i heard, i -- i started crying. >> reporter: alexis' parents were among the lucky. her mom said when she arrived at the firehouse, alexis was already with her father. >> he had her in his arms. and crying. and so she is just, she goes mom, i'm okay, i'm here. >> reporter: the rampage and evacuation happened in a flash. but we wouldn't know the full scope of the horror for hours.

>> the shooter is deceased. deceased in the school. >> reporter: by 10:30, president obama was briefed on the situation and schools throughout the area were on lockdown. police were surrounding a second crime scene, the shooter's mother's home, nearby. at around noon, the horrifying numbers were announced. abc news learned that lanza had killed 27 people. most of them children. at the local hospital, they were bracing for an onslaught, but they only got three patients. two of whom died. >> a number of us imagined what it may have felt like on 9/11. when there were people bracing for scores of injured and they didn't arrive. >> reporter: at the firehouse where students were gathered waiting for their parents, we met another mother whose children go to a nearby school. she told us she was here to support her friend and to put off picking up her own children because she didn't want to tell them about this massacre. >> this is the last two hours of their life that they're going to be a kid.

>> i know there's not a parent in america who doesn't feel the same overwhelming grief that i do. >> reporter: shortly after 3:00 in the afternoon, the president addressed the nation. >> the majority of those who died today were children. beautiful little kids between the ages of 5 and 10 years old. among the fallen were also teachers. men and women who devoted their lives to helping our children fulfill their dreams. >> reporter: not long after that police announced lanza had shot his mother, who was believed to have worked at the school at some point, at her home before he then went and stormed the school. >> we need to answer every single question to determine exactly how and why this incident occurred. >> reporter: tonight at the capitol building in washington, flags lowered to half staff. while back in newtown, true to the grim and all too familiar script of the mass shootings, a candlelight vigil. all day long as we watched the

drama unfold here, adding to the shock in this community, the fact that this is such an unlikely venue for violence. a small, sleepy town, with a population of fewer than 30,000, the kind of bucolic new england place where people move precisely for the schools and the safety. >> like, should i be pinched to see if it really is real? i'd just -- heartwrenching. >> reporter: feels like a dream, a bad dream. >> it's a nightmare. >> reporter: for though lucky enough to be reunited with their children tonight, a wake-up call. >> count your blessings every day for what you have. >> reporter: alexis, i am really glad you're okay. really glad you're okay. you're pretty tough. you're pretty tough. she is a great kid and she's had a very tough day. and tonight, abc news has learned that the fbi is interviewing friend and family of the gunman not only here in connecticut but also in new jersey and in massachusetts as they try to go about answering the big, burning question -- why?

what was his motive? cynthia. >> thanks to you, dan harris reporting. next up, heroes in the midst of terror, the brave teacher who locked her first graders in the classroom bathroom and promised them they would make it to christmas. >> we just have to be absolutely quiet. and we have -- i said, there are bad guys out there now and we need to wait for the good guys. change engineering in dubai, aluminum production in south africa, and the aerospace industry in the u.s.? at t. rowe price, we understand the connections of a complex, global economy. it's just one reason over 75% of our mutual funds beat their 10-year lipper average. t. rowe price. invest with confidence. request a prospectus or summary prospectus with investment information, risks, fees and expenses to read and consider carefully before investing.

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this special edition of "nightline," tragedy at the elementary school, continues with cynthia mcfadden. >> well, far too many innocent lives were lost today at the elementary school here in connecticut. it is impossible to know how many children were saved by the courageous actions under fire by the sandy hook elementary teachers and staff. the stories of heroism are only beginning to unfold. abc "world news" anchor diane sawyer met one young teacher with an extraordinary story. >> i knew it was a shooting immediately. >> it was just repetitive sounds? >> yeah, it sounded like the type of gun that just shoots over and over and over again. i told all of my students that we had to get in the bathroom. it was all i could think of. i put one of my students on top of the toilet. i just knew we had to get in there. i was just telling them it's going to be okay, you're going to be all right.

i pulled the bookshelf before in -- before i closed the door in front of it, so we were completely barricaded in, turned the lights off. >> did you tell them to be quiet? >> oh yes. i told them to be quiet. i told them we had to be absolutely quiet because i was just so afraid that if he did come in and then he would hear us and he would maybe start shooting the door. i said we have to be absolutely quiet. and we have -- i said, there are bad guys out there now, we need to wait for the good guys. i wanted us to be okay. and i'm so saddened that there are people in this situation who are not okay. and my heart goes out to anyone who knew them and was part of their lives. i just can't imagine. >> did they cry? >> if they started crying, i would take their face and say it's going to be okay. show me your smile. i really tried to -- one of my students would say things like i

know karate, so it's okay. i'll lead the way out. >> they said to you we want to go home for christmas. >> oh yeah. oh, yeah. uh-huh. yep. i just want to hug my mom, just things like that that were just -- just heartbreaking. you know? in my mind -- because you're hearing -- i've never been part of something anywhere near this traumatic. and so i'm hearing the gunfire in the hallway. i'm thinking in my mind -- i'm thinking i'm the first classroom. why isn't he coming -- i'm thinking we're next. in my mind, i'm thinking as a 6-year-old, 7-year-old, what are your thoughts? i'm thinking that i have to almost be the parent. i have to tell them -- you know. so i said to them, i need you to know that i love you all very much. and that it's going to be okay. because i thought that was the last thing they were ever going to hear. i thought we were all going to die. and i don't know if that's okay -- you know, teachers.

but i wanted them to know someone loved them and i wanted that to be one of the last things they heard. not the gunfire in the hallway. it's just so horrible. it's just so horrible. horrible, horrible. >> how did you know you were going to be okay? >> i didn't. what finally happened was the gunfire stopped. the gunfire wasn't that long. so that stopped. but i said we're not going anywhere. we're staying here until someone good comes in and gets us out. so eventually what happened was the police came and started knocking, and obviously i was completely beside myself. and i said, i don't believe you, you need to put your badges under the door. so they put their badges under the door. i said if you're really a police officer, then you would have a way to get in here. you would have a key or you -- if everything's okay, you would have found the keys. so he had the keys and he found the right one and he unlocked the door and then they brought us out to the firehouse to meet up with the rest of the teachers and students waiting for parents to come and pick them up.

>> i think there are a lot of people who wish that -- want all the teachers to know how much it means to them, how much they care about their children. >> uh-huh. how could you not? >> thank you. >> thank you. >> our thanks to diane, and one teacher's remarkable bravery. but she wasn't the only one inside sandy hook elementary whose quick thinking and instincts helped so many children out of harm's way. abc's amy wobach reports from outside danbury hospital to bring us the many heros who emerged today. amy? >> reporter: tonight, cynthia, we are learning more about the victims of today's deadly rampage. among the 20 children and six adults killed today, we now know that the school's principal, dawn hochsprung, was among those killed. parents describe her as a loving and caring educator who was always excited about the children in her school.

we now know the teachers who she led made a big difference today saving lives. for more than 600 students who attend sandy hook elementary school, it is the teacher's words they followed day in and day out. today those words might just have saved their lives. >> teachers did get them in a single line format. they told them to put their hands over their eyes as they exited in the school and quickly walked them down the street to the firehouse. >> reporter: today amid the horror, stories of extraordinary courage and heroism. teachers who barricaded doors ended up in the line of fire, led their students to safety. richard wilford's 7-year-old son is in the second grade. >> his teacher went and checked. she came in, closed and locked the door. they went into a corner until they were recovered by police. >> my daughter's teacher heard some shots and immediately locked the door. the state police came and knocked on the door and told them it was safe to leave. >> reporter: the facts are still emerging about what happened. there was this tweet this

morning, an assistant principal shot twice and in surgery. and this face telling it all. this woman's sister, one of those teachers inside the school, her whereabouts unknown. >> it does sound as though that the teachers did everything humanly possible, down to risking their own lives, to protect the children in this connecticut school. >> reporter: being prepared is increasingly becoming part of the new math of classrooms nationwide. >> teaching kids to lock down, securing your rooms, and in some cases teachers stepping forth to protect the children at the risk of their own life is something that we see occurring more and more over the years in school safety. mass parent notification systems are a critical part of school emergency planning today. >> reporter: in fact, just this year, sandy hook elementary school put into place a security plan, making it mandatory for visitors to ring a doorbell and only be let in if staff recognized them through the video monitor. and if staff didn't recognize the visitor, he or she needed to

present picture i.d., sign in, and only then would be let into the school. >> it really has to be a combination of notification, then the school, the teachers, the students, and law enforcement have to be very clear about what their roles are during an active shooting. so that really goes to training. >> reporter: this is at least the 31st school shooting in the united states since the stunning rampage 13 years ago at columbine high school. >> elementary schools across the country have been preparing for lockdown drills, evacuations and other security measures since columbine. we're not going to teach children to attack armed intruders and throw pencils and notebooks, but we do expect to have school staff trained on locking down, on evacuation procedures, working with law enforcement on active shooter drills and those are the things that are important. >> there's little defense against someone who's willing to die that arrives at a school

with multiple firearms, body armor, and willing to kill anybody that gets in their way. but the real key is because you can't maybe stop that, you clearly can reduce the number of people injured or killed with proper movement, which is the result of training. >> there's no words that i can come up with that would even come close to describing the sheer terror of hearing that your son is in a place or your child is in a place where there's been violence. you don't know the details of that violence. you don't know the condition of your child. and you can't do anything to immediately help them. it is a powerless and terrifying experience. >> reporter: here at danbury hospital, we know that 80 doctors and nurses were anxiously awaiting to treat as many as two dozen wounded victims from today's shooting. sadly, only three arrived, and even more tragic, we now know two of those victims have since died. both of them children. a crushing blow to this community. cynthia?

>> thanks, amy. next up, who could do this, and why? what we know about the 20-year-old gunman behind the tragedy. sometimes life can be well, a little uncomfortable. but when it's hard or hurts to go to the bathroom, there's dulcolax stool softener. dulcolax stool softener doesn't make you go, it just makes it easier to go. dulcolax stool softener. make yourself comfortable.