Updated 9:28 p.m. ET
A tractor trailer and a CSX cargo train collided Tuesday afternoon, derailing about 15 train cars, rocking the Baltimore region with a huge explosion and sending a plume of smoke into the air that could be seen for miles, CBS News affiliate WJZ reports.
CSX spokesman Gary Sease said the train was en route from Silkirk, N.Y., to Waycross, Ga., when it collided just after 2 p.m. in Rosedale, just northeast of Baltimore City. Shocked residents said the ground shook and windows were blown, leading many to think and earthquake occurred or bomb had gone off.
The truck driver, 50-year-old John J. Alban Jr., was in serious condition Tuesday night, a hospital spokeswoman said. Two CSX workers aboard weren't hurt.
Hazmat teams were on the scene, but Baltimore County Executive Kevin Kamenetz said at a news conference that no toxic inhalants were burning. Officials did not order an evacuation.
Dale Walston said he lives about a half-mile away and that he thought he could smell chemicals.
"It shook my house pretty violently and knocked things off the shelves," he said in an email to The Associated Press.
The face of one warehouse near the train tracks blew off.
And even hours after the blast, the thick plume of black smoke drifted across the Baltimore city line and covered the eastern part of the city. Shortly after 6:30 p.m., the plume lightened considerably, changing from black to gray, and its intensity diminished. Firefighters had been battling the flames for an hour and a half after initially considering letting the cars burn out.
Sease said in an email that on one of the cars was sodium chlorate, which the Department of Transportation classifies as a hazardous material. However, Baltimore County Fire Chief John Hohman said the chemical was not in one of the cars that was burning into the evening. The bleaching agent is used in making paper.
Nick Materer, an Oklahoma State University chemist and chief science officer at ExploSafe LLC in Stillwater, Okla., said sodium chlorate, when combined with fuel, makes a more volatile mixture.
"When you mix them together and add fire they go boom," he said in a phone interview.
Materer said the chemical is usually shipped as a white powder but it can also be in a liquid solution. Either way, he said, the fumes can irritate the lungs if inhaled.
Exactly what triggered the explosion was being investigated, and Hohman said firefighters were informing residents of about 70 nearby homes that they could leave if they choose and shelter will be provided.
Earlier, fire officials had said buildings had collapsed, but Hohman modified that to say two warehouses were heavily damaged by the explosion and other buildings were harmed, but none collapsed.
An Amtrak spokeswoman said its Northeast Corridor service was not affected.
A WJZ viewer told the station he was about a quarter of a mile away at his friend's house when the explosion happened.
"We went outside of his house, which is right on the top of Route 40 at Philadelphia Road. We were watching the fire, and then all of a sudden the explosion happened and actually knocked me off my feet. The window broke out in his house. You could feel the heat on our faces. I never seen anything like it," he said.
A customer at a nearby print shop said windows blew out and ceiling fixtures fell, and at least 100 people were evacuated from the store. Some thought that a bomb had gone off.
And a neighbor who lives just around the corner from the epicenter of the blast said she was working when she heard the loud explosion.
"Boom! And that rocked the house," she told WJZ.
"The whole house shook. The glass doors all shook. I shook," she said. "It was a jolt like the earthquake we felt. We kind thought it was something like that."