Several train cars carrying volatile chemicals derailed and exploded Tuesday south of Louisville, shutting down a nearby highway and forcing evacuations of homes, businesses and a school, authorities said.
There were no immediate reports of injuries from the wreck that occurred about 8:45 a.m. EST, but the fumes caused several people to seek treatment at a local hospital, authorities said.
The blaze produced a massive column of black smoke in the mostly rural area. Television footage showed several blazing cars stacked across the rail lines and flaming liquid flowing down ditches from the mangled tanker cars.
At least eight tanker cars were burning, Bullitt County sheriff's detective Scotty McGaha said.
Three cars involved in the fire were carrying chemicals including cyclohexane, Bullitt County Emergency Management spokesman Jeremey Urekew said. The chemicals are volatile, but don't pose a serious health threat, Urekew said.
"These substances themselves are pretty toxic, but when they burn they break down a whole lot," Urekew said. "This fire is going to burn itself out."
Two other cars were carrying hazardous materials that could pose an environmental threat, but they were not near the fire, he said.
CSX Corp. spokesman Gary Sease said the train with four locomotives and 80 cars was headed to Louisville from Birmingham, Ala. Sease had initially said the cars were carrying liquid propane gas, but later said that information was inaccurate.
Forty-one cars were loaded with freight and the rest were empty, Sease said.
A witness told CBS affiliate WLKY that she was driving near the railroad tracks, and saw the train shake and then flip over. She added that a "huge" explosion followed the crash.
The immediate area, including Brooks Elementary School, was evacuated, said state police Maj. Lisa Rudzinsky. She did not give the radius of the affected area, which has residential, industrial and rural properties.
Authorities also shut down an 18-mile stretch of Interstate 65, Kentucky State Police dispatcher Joey Mattingly said.
Eleven people were treated at a hospital for symptoms related to the fire, hospital spokesman Brian Doheny said.
The Kentucky National Guard said it mobilized 20 to 25 soldiers and airmen to check air quality.
Bullitt County resident Daymon Strange said he was outside his home less than a half-mile from the crash site when he heard an explosion.
"I turned around and looked and there was fire at least 500 feet in the air," he said in a telephone interview. "I've never seen such a fire. It was huge."
Strange said he smelled the fumes even though they were blowing away from his home.
"You can taste it and feel it in your lungs when you go outside," he said.
Gov. Ernie Fletcher, who flew over the area with the Kentucky Air National Guard, said he has not determined whether a state of emergency will be declared.
It was the second fiery train crash in Kentucky in two days. On Monday, four runaway rail cars struck two parked locomotives in central Kentucky, catching fire and spilling a chemical that prompted a limited evacuation.