TEMPE, AZ — Officials confirm Wednesday's train derailment in Tempe was the second time a Union Pacific train had derailed on the bridge over Tempe Town Lake in recent weeks.
The train was hauling lumber and other chemicals when it derailed and caught fire early Wednesday morning while crossing a bridge over Tempe Town Lake, which caused a portion of the bridge to collapse.
In a statement released Wednesday afternoon, Union Pacific officials confirmed on June 26, 2020, one of its trains hauling 12 railcars derailed during the afternoon hours. Rail and bridge ties were damaged, the spokesperson said. The track reopened two days later. No other information was released.
In Wednesday's incident, more than 90 firefighters from the Tempe Fire Department and other nearby agencies responded to the southern portion of Tempe Town Lake where they found several train cars on fire. Flames could be seen running the length of the bridge, sending dark clouds of smoke billowing into the air near Tempe Beach Park.
Several firetrucks were seen spraying water on the flames for several hours Wednesday morning, while a fireboat was helping to spray water onto the flames and remnants of the fire from the lake.
Tim McMahan, a spokesperson for Union Pacific Railroad, said in an email that eight to 10 train cars were reported to be on fire. He said none of the train's crew were injured, but a firefighter was treated for smoke inhalation.
When the south side of the bridge collapsed, three tank cars fell below it. Two of those cars were hauling cyclohexane and the other was hauling a rubber material. According to the National Center for Biotechnology Information, Cyclohexane is a “clear colorless liquid with a petroleum-like odor” that is sometimes used to make nylon or used as a paint thinner.
It is considered to be a highly flammable chemical that can cause skin irritation, dizziness, or death, if swallowed. It is also considered to be “very toxic to aquatic life,” according to the NCBI.
Tempe Fire Chief Greg Ruiz said the chemical was not leaking into the lake, but into a dry bed beneath the bridge. He said crews were working to stop the leak, but did not have a timeframe for when that would take place.
Initially, a spokesperson for Union Pacific said none of the trains that fell off the bridge were reported to have been leaking.
The cause of the derailment remains under investigation, officials said.
Investigators with the Federal Railroad Administration have been sent to the derailment site to "start a preliminary investigation," a statement said. "Further updates will be provided at a later time," the FRA released in a statement.
People should expect investigators and emergency officials to be in the area for a while.