ST. JACOB

A toxic chemical spill caused by a train derailment Tuesday afternoon near here forced the evacuation of residents from about a dozen homes, authorities said.

About 20 cars of a 131-car train operated by CSX Transportation left the tracks about 3:30 p.m. The site is about 20 miles east of St. Louis and four miles west of St. Jacob, near the intersection of U.S. Highway 40 and Triad Road.

Investigators were working Tuesday night to determine the cause of the derailment. No one was injured, police said.

  bleaching agent hydrogen peroxide and the fertilizer ammonium nitrate were leaking from the ruptured rail cars, said Capt. Rob Hancock of the Troy Fire Protection District. A white vapor spewing from the accident scene was produced by the chemical mixture of hydrogen peroxide releasing into the air.

Emergency workers evacuated a half-mile area around the accident scene, Hancock said. At least two of the derailed cars bore labels for anhydrous ammonia, a potentially deadly toxin which can sear eyes and lungs. Those cars holding anhydrous ammonia were not breached in the accident, Hancock said.

Investigators said the ruptured train cars had stopped leaking by Tuesday evening and posed little threat to the surrounding area.

Evacuees Dan and Cindy Duff, who live about a quarter-mile from the accident, said they saw smoke in the air and heard a sizzling sound after the train derailed. The Duffs were headed to stay with Cindy Duff's sister-in-law in Granite City.

"We don't know when we can go back home," she said.

A hazardous materials team was expected to continue assessing the accident into early this morning.

CSX spokesman Robert Sullivan said the train was going to Indianapolis from St. Louis. The train included two engines and was carrying a variety of materials. CSX Transportation operates on 21,000 miles of track in 23 states east of the Mississippi River.

Sullivan said CSX had hired a private hazardous-materials firm to assist Madison County with the cleanup and was sending its own teams as well. "We're funneling all resources we can to protect the public," he said.

Sullivan said the company would look into the cause of the accident after immediate safety concerns are addressed.

"The first thing we're going to do on a case like this is focus on what's happening at the derailment," he said. "Once we've got that under control, we will begin a full investigation as to how this happened."

An Illinois Emergency Management Agency official was evaluating the scene Tuesday night, said Patti Thompson, an agency spokeswoman. The agency can offer advice and state assistance if needed. The Illinois Environmental Protection Agency would be involved in cleaning up any chemical spill.

Among those evacuated were Ray and Kelly Malone, who sat at the corner of Highway 40 and Illinois Route 162, wondering when they'd be allowed to return to their house, about 800 feet away.

Ray Malone, a machinist, was heading home from his job in St. Louis at around 4:20 p.m. Tuesday when he saw that Highway 40 was closed to traffic, with several police squad cars and emergency vehicles in the area.

"Right now, we're just waiting," Malone said. The couple said they hoped to get back to their house soon for supper and a shower.

Greg Jonsson and Adam Jadhav of the Post-Dispatch contributed to this report.