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."
Derailments have done great damage before in Baltimore, a city with countless train tracks. Twelve years ago was the derailment and chemical fire in Baltimore's Howard Street tunnel. Rail cars burned for five days underground in July 2001. Portions of downtown were closed and rail traffic across the U.S. was affected for days. CSX eventually agreed to pay Baltimore $2 million to help defray the city's cleanup costs.
The National Transportation Safety Board and the Federal Railroad Administration were sending teams to investigate Tuesday's crash.
Police would investigate the circumstances that led to the track collision, but it was not clear what, if any, charges the truck driver or anyone would face, said Elise Armacost, a county spokeswoman. Police and fire officials said they were not sure how the trash truck got on the tracks or even whether it was at a crossing when it was hit.
Photos showed at least a dozen train cars off the tracks, including at least one tanker car. Sease said four of the cars believed derailed carried terephthalic acid, which is used in the production of plastics and polyester, among other things. He said it is not listed as a hazardous material.
One of the cars still burning was carrying terephthalic acid, and another was carrying fluoroacetic acid, Hohman said. Fluoroacetic acid is an "extremely toxic" constituent of many poisonous plants that is used to make products that kill rodents and deter coyotes, according to the National Institutes of Health website. It produces poisonous gases when burned, according to the NIH.
Materer said the gases contain chlorinated organics. He was less familiar with terephthalic acid but said it, too, contains chlorine.
"It just doesn't sound good," he said.
Hazardous materials moving through Baltimore and elsewhere in Maryland was the subject of an agreement a few years ago between the state and CSX. After a November 2007 derailment involving a freight train carrying hazardous materials near Camden Yards, CSX agreed to give security officials real-time information about potential harmful cargo moving through the state on freight trains. Railroads had previously guarded such details as proprietary information.
Also hit by a serious derailment this month was Bridgeport, Conn. On May 17, more than 70 people were injured when a commuter train went off the tracks. The eastbound train from New York City derailed during evening rush hour, came to a stop and was struck about 20 seconds later by a westbound train.
In Rockview, Mo., on Saturday, a cargo train crash injured seven people and destroyed a highway overpass that could take a year to repair.
Despite the high-profile railroad accidents, the overall number of such crashes has been declining industry wide and for CSX over the past decade.
Last year was the safest year on record for the railroad industry, according to the railroad administration. All train accidents are down 43 percent since 2003, and derailments are down 40 percent over the same period, according to data provided by the administration. Freight train derailments specifically are also down 40 percent.
In each of the past five years, CSX has reported more than 100 deaths in accidents and incidents involving the railroad.
CSX, based in Jacksonville, Fla., operates over 21,000 miles of track in 23 eastern states and two Canadian provinces.
Its shares traded higher Tuesday before the derailment was reported. The shares closed down 20 cents at $25.30.
Bertha Pressley and her husband Tom Brown said their townhome in Middle River, about 3 miles away, shook and they initially feared a bomb or natural disaster.
"I thought it was terrorism," Pressley said.