correspondent allison harmlen is in new york. >> reporter: bell rang out ahead of the first moment of silence at the world trade center to mark 13th anniversary of the 9/11 terror attack. >> michael patrick tucker. >> lance richard. >> reporter: as is tradition family members read names of the nearly 3,000 victims. >> we love you and we miss you and we will never forget you. >> reporter: president obama paid tribute to those kill in the ceremony at the pentagon memorial. >> we carry on because as americans we do not give into fear. >> reporter: there is also a service in shanksville, pennsylvania for victims of flight 93. engine 54 lost 15 fire fighters on 9/11, more than any other firehouse. every year on the anniversary the families come back to take comfort in each other. >> they are all hurting like we are and it never is getting over it. >> reporter: maureen lost her son, lenny, her younger son steven, who was only ten in 2001 grew up to become a fire fighter. >> engine 54 like his brother and same badge number that lenny had. we're very proud of him. >> reporter: maureen, who lo

cbs reporter allison harmlen has more outside nfl headquarters in new york, we made a mistake, and we needed to get this right. >> reporter: that was refrain. of minnesota vikings officials repeated over and over, after they reversed their decision to allow running back adrian peterson to return to the field this weekend. team acknowledge it sidelined the super star after outcry from fans and corporate sponsors. peterson facing child abuse charges for whipping his four year-old son with the tree branch agreed with the teams decision. >> he felt it was best for him to be able to step away to take care of his legal and personal matters. >> reporter: nfl commissioner roger goodell now under investigation for his handling of the ray rice domestic violence case but peterson on the exempt commissioner's permission list. the exempt list is a special player status that set aside for unusual circumstances. it requires peterson stay away from his team until charges against him are resolve but he will continue to collect his $695,000 per game check. peterson was not the only absence from the vik

cbs news correspondent allison harmlen looks at a program that monitors new york city fire fighters,d new york city fire fighter lieutenant terence jordan requires oxygen 24 hours a day. he has severe lung disease. >> i developed copd, emphysema, asthma, bronchitis, sleep apnea. >> reporter: he spent days at ground zero searching for survivors, and even helped rescue a fellow fire fighter. >> that is our job, you know, we're there to help people, save people. >> reporter: in the past 13 years 89 new york city fire fighters and emergency medical services workers have died, from illnesses related to their exposure on 9/11. what do we know about what was in the air that day. >> world trade center dust is a complex mixture. >> reporter: doctor david, heads up the world trade center health program that monitors 16,000 fire fighters, and e ms workers. >> we do treatment for both respiratory conditions, mental health conditions. >> reporter: cancer is also a big concern, the program is seen more than 800 cancers related to ground zero, exposure. >> and, we can improve, their quality of life