nbc news, seattle. >> terrific story to end on tonight, as we welcome diana alviar. >>> dr. snyderman will have a special report on the increasing challenges for the millions of us who have been this rust into the role of caregiver at one time in our lives. especially those caring for aging parents. that's tomorrow night here on nbc nightly news. that is our broadcast for this tuesday night. thank you for being here with us. i'm brian williams. we hope to see you right back here tomorrow evening. good night. -- captions by vitac -- www.vitac.com

nbc's diana alviar has more from los angeles. >> this is horrible.eporter: velma causey is desperate to find her daughter. she's been watching search teams comb the waters rebecca weiss was reportedly free diving last saturday, using just a wet suit and a snorkel. the last day her husband says he saw her. alan weiss told investigators his wife of 18 years left their condo wearing her wet suit. when she did not come home, he went to the cove they often free dive together. he didn't find rebecca, only her diving bag and car. that's when alan reported her missing. homicide detectives are reviewing surveillance video from businesses in the area where alan said he thinks his wife was headed. they tell nbc news he's cooperating with their investigation and not considered a suspect in his wife's disappearance. however, rebecca's family says they're having a hard time believing her husband's story and that she knew better than to free dive alone. >> my sister is a strong swimmer, and she was wearing a wet suit, you know, according to my brother-in-law. so, i

for "today," diana alviar, nbc news, los angeles. >>> a violent accident on a mississippi highway turneds dozens of drivers put their own lives on the line to pull two women from a fiery wreckage, an associated press photographer was able to capture the dramatic moments after wrapping up his role as rescuer. we get details from nbc's mark potter. >> back up. >> reporter: moments after an suv careened out of control, struck a tree and caught fire in a highway median strip, 15 to 20 fellow motorists stopped their cars and rushed to help. the woman suffered severe head injuries. her sister who is disabled was strapped in the back seat when navy petty officer melissa estes arrived on scene, she found both of them in extreme danger. >> i remember i started yelling for fire extinguishers because that's when i realized the entire front of the suv was engulfed in flames. >> reporter: associated press photographer gerald herbert arrived shortly afterwards and saw the driver trapped behind the wheel begging for help. >> that was one of the most horrible feelings in my life, to run up there and see