WASHINGTON (WUSA) -- It sounded like a bomb, and a lot of people thought it was a terrorist attack. A big, empty yellow school bus being used by the military exploded in flames just before noon.
The bus was hooked to a tow truck and it started burning in perhaps the worst possible place: in the 3rd Street Tunnel by the Capitol, with dozens of cars trapped in the tunnel with it.
Traffic is moving again now, and the three Capitol Police officers who inhaled a ton of smoke have all been released from the hospital.
But can you imagine anything more terrifying than being trapped down in that black tunnel with people screaming and flames and smoke all around you?
"The smoke is coming fast now," says a guy on a YouTube video shot as he was trapped in the tunnel. "Do you think it was a bomb?" his passenger asks, just before they get turned around, and look back to see what looks like the bus in flames.
"What was scary was the smoke. The smoke was bad," Rev. Vernon Burch told us from the safety of Washington Ave. above the tunnel.
Firefighters think a mechanical malfunction set off the fire that all but destroyed the bus, which was empty and under tow. Some suspect someone failed to release they brakes before they started towing it.
Rev. Burch was among the scores of drivers who were desperately trying to turn around and escape. "When he backed into the the front and I had to stop, the guy hit me in the back," he says, pointing to his dented BMW . "I got kind it from both ends."
The police ordered thirty or so people out of their cars and up the ramp. "We could not advance, smoke was into the car. The bus could explode any moment," says Miguel Angulo, who was stuck with his wife and two young children.
Police finally let the drivers back down to get their cars... all of them were ok. And after a couple of hours cleaning up the mess, DDOT finally re-opened the tunnel.
But for the Angulo family, who were visiting from Peru, this is something they'll never forget. "You think about them," says the dad, hugging his children. "The little one was very nervous."
I talked by phone with Andy Maybo, one of the officers who was rushed to the hospital. He was hacking and coughing and clearly shaken. He was there when the bus burst into flames, and he says the smoke was so thick you literally could not see your hands in front of your face.
But he says there was no way he was leaving until he got all those people out of there safely.
Written and Reported by Bruce Leshan
9News Now & wusa9.com