About half a dozen local, state and federal agencies are investigating what caused a train crossing over Tempe Town Lake to derail and catch fire this week.
Union Pacific Railroad, which operates the train, is conducting its own internal investigation into the cause of the derailment, which caused the partial collapse of a more than 100-year-old railroad bridge that crosses the lake.
Investigators with the National Transportation Safety Board and the Federal Railroad Administration, which regulates and inspects the railroad industry, were also on scene Thursday to determine what led to the crash.
It likely will be weeks or longer before a cause is known.
“We are all working with local, state and federal authorities to determine the derailment’s cause,” Lupe Valdez, a Union Pacific spokesperson, said during a news conference. “We do not have that information at this time.”
Valdez said the situation was “challenging” and apologized to the community for the derailment’s impact on rail services and street closures in the area.
Eight to 10 cars carrying lumber and hazardous materials derailed shortly after 6 a.m. as the 102-car freight train made its way across the bridge over Tempe Town Lake early Wednesday.
The bridge’s south end collapsed, sending three cars into the empty park and Rio Salado Parkway below. The incident temporarily halted flights into Phoenix Sky Harbor International Airport and Valley Metro light rail service over the lake.
About 500 gallons of cyclohexanone leaked from one of the cars, which can carry between 25,000 to 30,000 gallons of materials. The leak was contained by Wednesday night.
Union Pacific said it hoped to have all the cars removed from the railroad by Sunday.
Valdez said Union Pacific intends to repair the bridge as it is an important part of its infrastructure in Phoenix. The company will assess the damage once the investigation is completed, and there was no timeline on when repairs would be done.
Federal agencies investigating cause of crash
Federal investigators asked Union Pacific and first responders late Wednesday night to halt work in the area so that they could begin their inspection.
The National Transportation Safety Board will be investigating the derailment and are in the fact-gathering stage, said Terry Williams, a spokesman.
“We are still in the very early stages of this investigation,” he said. “We would not be able to comment on anything that may have caused this accident.”
The federal agency investigates railway accidents that involve death, substantial property damage or significant environmental damage.
The NTSB typically releases a preliminary report that covers facts surrounding the derailment, including what the cars were carrying and whether any environmental factors in the area may have contributed to the accident.
The preliminary report is subject to change as the investigation proceeds.
Investigations typically look at track condition, examine the point of derailment and inspect previous track inspection records. Inspection records are examined to see if any conditions were documented that could have contributed to the derailment. Inspectors will also examine any “track disturbance reports,” which are documents that show when a section of the track has been disturbed and any corrective actions taken to resolve the issue.
The bridge was last inspected on July 9 and was found to be “in good standing,” Valdez, of Union Pacific, said. The company has turned over inspection records to federal investigators, she said.
Investigations can take more than a year. An investigation into a NTSB report freight train derailment that happened in May 2018 in Alexandria, Va., took nearly two years to become public.
While NTSB investigations often determine a “cause” or “probable cause” of the accident, the review isn’t designed to point fault or blame. The federal agency’s mission is to improve transportation by investigating accidents and issuing safety recommendations. NTSB reports also can’t be used in civil courts to determine damages.
Like the NTSB, the Federal Railroad Administration also investigates the cause of serious railroad accidents that lead to an employee or passenger death or property damage.
The agency said five inspectors were on site investigating the accident. Union Pacific has 30 days to submit an incident report to the FRA, and that report will be made public by October
Inspectors will look at any issues with the track or railroad infrastructure, locomotive and rail cars, signal and train control systems and operating practices. They will review inspection and maintenance records and employee training.
The Arizona Corporation Commission, which regulates railroad crossings in the state, will assist the FRA with its investigation and conduct its own state-level investigation, Tempe Fire Chief Greg Ruiz said at the Thursday news conference.
The Corporation Commission sent hazmat, track and mechanical inspectors to the accident on Wednesday.
Police on the ground
The Tempe Police Department, with help from the FBI, is also investigating the derailment, police Chief Sylvia Moir said.
Moir said while there is nothing to indicate the derailment was caused by a criminal act, officers are collecting evidence just in case.
“At this time there is nothing to suggest that this is anything other than a structural derailment,” she said on Thursday. “But we take very seriously our responsibility to ensure that our investigators are on ground, preserving and collecting anything that would be of use if this rose to a criminal investigation.”
Reach reporter Paulina Pineda at firstname.lastname@example.org or 480-389-9637. Follow her on Twitter: @paulinapineda22. Reach reporter Anne Ryman at email@example.com or follow her on Twitter at @anneryman.
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