Train Derails in Columbus, Ohio, 100 Homes Evacuated Mile-wide area of city is being evacuated as authorities try to contain blaze.

July 11, 2012 -- A mile-wide area of Columbus, Ohio, is being evacuated as authorities attempt to contain the blaze caused this morning by a freight-train derailment and explosion.

About 100 homes have been evacuated after 11 cars of 98 on a train headed south through the city derailed around 2 a.m. today, near Interstate 71. The accident took place southeast of the Ohio State University campus.

A command post is being set up at the Rhodes Center at the Ohio State Fairgrounds, where the evacuees are being taken, ABC News affiliate WSYX reported.

Two of the train cars were on fire at 5:30 a.m., WSYX reported. The train was reportedly carrying denatured alcohol and styrene, a chemical used to make plastic. Hazmat officials called to the scene said that there was no risk for air contamination, WBNS-10TV reported.

It was not immediately clear what caused the crash.

Two people who ran toward the scene before the explosion were reportedly injured, but were able to get to the hospital themselves, Battalion Chief Michael Fowler told The Associated Press.

The fire could take until after noon today to burn out completely, officials told WSYX. Residents won't likely be allowed to return to their homes before late evening, if at all, according to city officials.

Photographer Chris Mumma, who was in the area at the time, told The AP that he noticed a chemical smell in addition to the smoke in the air. He said that although he was 10 miles away, he was able to see the sky light up after the derailment.

"I noticed there was a chemical smell, and I was inhaling it so I backed up a little bit more because I wasn't sure what I was getting involved with," he said.

Mumma said that the odor made him so nauseous that he ended up at the hospital.

Fowler told The AP that authorities will have a better sense of the scope of the scene when the sun rises.