chuck sievertson has the latest. >> reporter: investigators are combing the area, searching for crews to the fiery explosion from a fed ex tractor-trailer slammed into a tour bus full of college-bound high school students. the bus driver made defensive maneuvers to avoid the truck. >> there was action on the part of the driver to stop the vehicle. they are also saying there was a reaction beyond just the braking, the serving to the right. >> and a woman saw it strike the truck. >> it was coming straight toward me. the driver reported seeing flames underneath the tractor-trailer before it everybody swerved across the median and into the oncoming bus. >> the southbound lane at a 10-degree angle, and there are no tire marks, which would be no braking tire marks in the median or the northbound lanes. >> this charred, mangled shell, claimed the lives of ten many people and injured others. the bus was only in service about a month and was equipped with seatbelts. some people were ejected, though. >> we are going to see whether the seatbelts kept them in place and caused for injuries. >> it

chuck sievertson has the latest. >> reporter: investigators are combing the area, searching for crews to the fiery explosion from a fed ex tractor-trailer slammed into a tour bus full of college-bound high school students. the bus driver made defensive maneuvers to avoid the truck. >> there was action on the part of the driver to stop the vehicle. they are also sag there was a reaction beyond just the braking, the serving to the right. >> and a woman saw it strike the truck. a driver reported seeing flames underneath the tractor-trailer before it everybody swerved across the median and into the oncoming bus. >> the southbound lane at a 10-degree angle, and there are no tire marks, which would be no braking tire marks in the median or the northbound lanes. >> this charred mangled shell, claimed the lives of ten many people and injured others. the bus was only in service about a month and was equipped with seatbelts. >> we are going to see whether the seatbelts kept them in place and caused for injuries. >> it is a bad nightmare. >> chuck sievertson, abc news, new york. >> we are learni

abc news reporter chuck sievertson has the latest. >> the reports of a chinese ship heard a pulse signal using the same frequency emitted by black boxes could be the break the world has been waiting for. >> this if that is sustained, in other words, if they heard it on a continuous basis, then they may actually have something. >> a kind niece plane also reported seeing debris near where the pulse was heard. now the multi-national fleet of planes and ships scouring the south indian ocean are in a race to find the ping quickly before the batteries in the flight and cockpit recorders fall silent. >> i think the warranty runs out sunday. we may get four or five days after that. and if they are really good batteries we might get a week or so longer but wear getting pretty close. >> two ships were launched to listen for the pings but they will need to be within one mile of the pings to hear them. a daunting task when the search covers 83,000 square miles, the size of kansas. authorities vowed not to give up in malaysia. >> we will continue to search. we owe this to the families of those on boa

abc news reporter chuck sievertson has the latest. >> the reports of a chinese ship her a pulse signal using the same frequency emitted by black boxes could be the break the world has been waiting for. >> this if that is sustained, they heard it on a continuous basis, they may have something. >> a kind niece plane also reported seeing debris near where the pulse was heard. now the multi-national fleet of planes and ships scouring the south indian ocean are in a race to find the ping quickly before the batteries in the flight and cockpit recorders fall silent. >> i think the warranty runs out sunday. if they are really good batteries we might get a week or so longer but wear getting pretty close. >> two ships were launched to lessen for the pings but they will need to be within one mile of the pings to hear them. a daunting task when the search covers 83,000 square miles, the size of kansas. they said they will not give up. >> we will continue to search. we owe this to the families of those on board. >> it's been nearly a month since malaysia flight 370 with 239 souls on board vanished