Chad Snow/KJZZ

A freight train traveling on a bridge that spans Tempe Town Lake derailed July 29, 2020.

A freight train traveling on a bridge that spans Tempe Town Lake derailed Wednesday morning, setting the bridge ablaze and partially collapsing the structure, officials said.

Video images showed huge flames and thick black smoke rising into the air and train cars on the ground near the lake.

None of the train's crew members were hurt but there was a report of someone suffering from smoke inhalation, said Tim McMahan, a spokesman for Union Pacific Railroad.

Tempe Fire Chief Greg Ruiz said multiple liquids were leaking out of several train cars. The fire department is working to contain a liquid called cyclohexane.

“The focus of the operation now is to contain a hazardous material leak from one of the cars. The hazardous material leaking is cyclohexane, which is a flammable liquid, it is used to produce other chemicals and solvents," Ruiz said. 

Ruiz said the leak is not spilling into Tempe Town Lake, and that the Fire Department is working with several government agencies to identify any environmental concerns in the area around the lake.

Tempe Police Chief Sylvia Moir said it will take a considerable amount of time before the area is cleaned up.

“I have listened to folks and heard from folks that say this will be multi-day, even perhaps a multi-week effort," Moir said. 

Moir added that the same is true for Tempe Town Lake as the city and Union Pacific repair the bridge while maintaining the lake’s quality.

Camille Kimball says she was on the bike path directly under the bridge, when she heard what she thought had to be a fighter plane from the local air force base. But it was the derailment.

“All the fiery debris fell down onto the bike path under the bridge, exactly where I had been. And I have to emphasize this is all in the space of one or two seconds,” Kimball said.

Tempe fire officials said the derailment happened at about 6 a.m. and that about 90 firefighters from Tempe, Phoenix and other fire departments were at the scene.

Some of the train's cars carried lumber and others were tanker cars, some carrying hazardous materials. McMahan said he did not know what was inside the tanker cars but that there were no reports of any leaks.

Detective Natalie Barela from Tempe police said it's too soon to speculate on the cause of the derailment.

Valley Metro light rail trains use an adjacent bridge to cross Tempe Town Lake. Buses will carry light rail passengers through Tempe while the bridge remains closed.

EDITOR'S NOTE: This story has been updated to clarify that Valley Metro light rail uses a separate bridge.