TODAY | December 20, 2014
>>> ongoing investigation into the deadly bus accident as more eyewitnesses come forward, officials are starting to put together the pieces of what happened. it could be a long time before they know for sure. janet shamlian is in chico, california, this morning with more. janet, good morning.
>> reporter: carson, good morning to you. there's new information that could advance the investigation. a couple whose car was sideswiped by the fedex truck say that truck was on fire before it crossed over the median and crashed into the bus.
>> i saw a very, very large explosion and fireball.
>> reporter: the impact was shocking.
>> oh, my god!
>> reporter: the damage, massive.
>> it is a fedex truck .
>> reporter: why that semi crossed the median on interstate 5 , slamming into a bus full of high school students is, this morning, still a mystery.
>> i know people want information regarding the investigation right away. that takes a lot of time. we may not have some answers for months on that.
>> reporter: earlier on "today," an ntsb member says investigators will look at whether the highway should have a median barrier .
>> we'll be looking at the criteria to determine whether or not there will be more here in this particular median.
>> reporter: for the students on board, it was terror, then chaos.
>> reporter: i was sleeping and then you just hear like, errr, and some girl screaming and then boom.
>> there's fire in front of the bus.
>> smoke everywhere. it was hard to see and breathe in there.
>> reporter: jonathan gutierrez says a simple decision he made earlier in the day may have been a life savor.
>> so we sat all the way in the back in the very last seat and i'm grateful we sat there, because the front of the bus was horrible. and i was like, wow, that could have been us.
>> reporter: among those who lost their lives, chaperone michael mybet and madison haywood, engaged in paris last year.
>> only one of them survived, the other would be an absolute wreck.
>> reporter: their dream ended on a trip, celebrating new beginnings.
>> parents and students are still here, and we're still trying to support everybody as best we can.
>> reporter: students were to spend the weekend touring humble state university for a look at their own future. christina serrato's identical twin sisters were on the trip. marisol arrived safely. marisa was in the bus that crashed and late friday their worst fears were confirmed.
>> we never thought that a normal, simple field trip they were going to take would end up in this nightmare.
>> both drivers were killed in the accident. ceo of fedex expressed condolences to the victims and the families and says that the company is committed to helping in the investigation. today in the season of prom and graduation, the families of five high schoolers are planning funerals. tragic.
>> it is tragic.
>> reporter: carson?
>> janet shamlian , thank you.