Two people were killed and two others trapped in a fiery crash between two freight trains that resulted in a chemical leak and forced the evacuation of nearby homes, authorities said.

The crash occurred at 6:15 a.m. in this community about 25 miles northwest of Detroit, said Sheriff's Sgt. Roy Coates. Authorities did not know what caust on Detroit television station WDIV showed one of those trapped being taken out of the train and transported in the back of a pickup truck along the railroad tracks. He appeared to be injured.

People living within a mile of the crash site were evacuated because of the risk from chemicals on the trains. A hazardous materials team was trying to determine what chemicals were involved, Coates said.

The accident occurred on a track operated by Grand Trunk, a subsidiary of Canadian National railroad.

Railroad spokesman Jack Burke said the two people who died were railroad employees whose names were being withheld pending notification of family.

He said chloride gas was on board, but he believed it had not leaked. If the gas leaked, authorities would be forced to extend the evacuation to a 1.7-mile radius, Coates said.

Mary O'Daniel, whose house is near the tracks, said she heard one train pass, then another.

"As the (second) train was going through, there was a rumbling and then all of a sudden, boom, boom, boom, boom," she said.

Some nearby schools were closed Thursday while authorities checked what was on the trains, Coates said.

National Transportation Safety Board investigators were headed to the site, said spokesman Terry Williams.

Erin Bellinger, 19, who lives near tracks, said she was concerned because she didn't have much information and police told her she may have to evacuate.

"Where do we go? What do we do? How far do we have to go before we can breathe the air? ... It's kind of crazy," she said.