Transcript for Bus carrying international students catches fire outside Boston
We turn now to a close call for dozens of foreign students visiting Boston when their bus caught fire forcing them to evacuate on a busy highway. David Kerley with the story. Reporter: The question this morning, what caused this frightening scene on the side of a highway just outside Boston? A coach bus engulfed in flames just feet away, nearly 20 international college students. They were on that bus moments before watching in shock as the vehicle board making a safe escape. The smell was pretty bad and the fire was getting bigger and bigger and almost like half of the bus was burned, already burned so I really scared. Reporter: Firefighters using axes to crush the bus windows out allowing water from their hoses to reach inside and stop the rapidly spreading fire. Hours later the bus was still smoking. The interior completely charred. Everybody was away from the bus when we got here. The amount of people on the bus we made sure. Reporter: The driver saying he thought he had blown a tire and pulled over to check it out and saw smoke rising from the back of the bus. We had military cadets on the bus and they got us to safety very quickly. Reporter: They were visiting tufts university and they waited next to the highway until another bus picked them up and took them back to campus. Quite a scene along that highway in Boston. At this point the bus company has taken the bus back to the shop. They're going to try to figure out exactly what did cause that fire, George.
This transcript has been automatically generated and may not be 100% accurate.