A small southern Minnesota town was evacuated for several hours after a train derailed Friday morning, spilling hazardous materials, authorities said.

The Union Pacific train traveling from South St. Paul to North Platte, Neb., jumped off the tracks near the town of Ellendale around 5:45 a.m. Several cars overturned, one of which was carrying highly flammable liquid propane, a railroad spokeswoman said.

Authorities said the 146-car train derailed 22 cars about a half-mile from town and forced a mandatory evacuation, sending officers door-to-door informing hundreds of residents that they should relocate to Ellendale United Methodist Church. They received the all-clear to return to their homes by 1 p.m.

An aerial view of the crash via news helicopter showed heavy smoke escaping what appeared to be the propane train car. The string of cars wrinkled, accordion-like, zigzagging back and forth off the tracks near farmland.

No injuries were reported.

Investigators worked for hours to contain a leak from a tear in a propane car, said Steele County Administrator Laura Elvebak. Another car carrying butane was not ruptured. Computer simulation is being used to assess the hazardous area and help develop a clean-up strategy.

"Union Pacific's priority is identifying the cause of the leak and maintaining it to preserve public safety," a company statement said.

By early Friday afternoon, authorities said the threat had largely dissipated, but continued to cordon off a 400-foot "hot zone" around the site. It remains unclear how long it will take for the railroad to remove the cars of mixed freight.

Union Pacific will be responsible for the clean-up and track restoration, according to the Steele County Sheriff's Office.

Schools were canceled Friday with the local district office posting a message on their website that there was "no way to get to the elementary building."

Randy Cirksena Jr., pastor of Ellendale United Methodist Church, said residents began arriving before 7 a.m. — many without any personal belongings — and eventually were served a meal by the Red Cross.

The facility has been a safe haven for stranded travelers in the past during winter storms and has nearly 100 mattresses stored on site. "We're prepared to take good care of folks," Cirksena said. "[Residents] have a can-do attitude. However they can help one another based on their core faith and family values, they do that."

The cause of the crash remains under investigation.

Ellendale has a long history with the railroad system. In fact, the town was created around it.

The town, founded in 1901, was named after Ellen Dale Ives, the wife of the president of the Burlington, Cedar Rapids & Northern Railroad — which traveled north to Minneapolis. The first business in the town was a depot.

More than 110 years later, multiple trains chug through the town each day.