Train derailment, bridge collapse under investigation in Tempe

Posted 7/29/20

Authorities are investigating after a freight train traveling from Tucson to Phoenix derailed along a bridge in Tempe, with that structure partially collapsing, according to officials.

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Train derailment, bridge collapse under investigation in Tempe


Authorities are investigating after a freight train traveling from Tucson to Phoenix derailed along a bridge in Tempe, with that structure partially collapsing, according to officials.

Tempe officials said the derailment happened around 6 a.m. Wednesday and that about 90 firefighters were at the scene.

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

A statement from Union Pacific says the south side of the Salt River Union Pacific Bridge partially collapsed, sending several rail cars on to an empty park below. Officials say eight to 10 rail cars were on fire. Officials say three tank cars were on the ground under the bridge. Two of them contained cyclohexanone — a pale and oily liquid that is toxic and flammable. The other had some kind of rubber material. None of them were leaking, and no tank cars were involved in the fire, officials said.

Police and fire officials did not report any on-the-ground injuries by any people congregating in the area for morning activities.

The incident initially started as a first-alarm hazardous incident but quickly upgraded to a second- and third-alarm, and as high as a fourth-alarm by 11 a.m., which Tempe Fire & Medical Rescue Chief Greg Ruiz says only happens in a very large event.

Mr. Ruiz said crews were working to contain any leaking of cyclohexane. However, none of the leakage was flowing into the lake but onto a dry bed, he said.

Mr. Ruiz added that the Arizona Department of Environmental Quality monitored the air surrounding the scene but found no imminent hazards. However, the chief says that it is still prudent for people to stay as far away from any smoke as possible.

Tempe police chief Sylvia Moir said they reached out to the FBI Phoenix Field Office as a courtesy as part of the early investigation.

Investigators with the Federal Railroad Administration were dispatched to start a preliminary investigation, the agency said in a statement. The National Transportation Safety Board will also investigate, officials said.

Anyone who witnessed or may have any information about the train derailment and fire can call 480-350-8311.

The bridge received its annual inspection July 9, according to Union Pacific. It was built in 1912, according to the city of Tempe. The bridge has survived while floods destroyed the previous three truss bridges constructed in the same location, the city says. It has been reinforced over the years, but has remained original in color and construction.

A phone call from a neighbor woke up Anthony Lamanna, program chair of the Del E. Webb School of Construction in the Fulton Schools of Engineering, who also lives in south Tempe.

“They’re going to have to inspect the entire bridge,” Mr. Lamanna said. “Fire doesn’t treat steel too well. It gets soft when it heats up and then when it cools down it actually changes in properties and can become very brittle. They’re going to have to inspect all the remaining parts of the bridge that were near the fire. And there’s a very good likelihood that the entire bridge will have to be replaced.”

Mr. Lamanna’s PhD and early career research was in bridge assessment, strengthening, and repair techniques, primarily funded by the United States Army, and some research work for the Louisiana State Department of Transportation and Development, per ASU. Not only did he work with U.S. bridges, he worked with bridges in other countries. Post Hurricane Katrina, he worked in the design of repair, retrofit, and adaptive reuse of structures.

“The biggest issue with most bridges is who owns them, who is in charge of taking care of them,” Mr. Lamanna said. “Railroad bridges are owned by the railroad companies, and their business is getting things from Point A to Point B across their bridges. So, there’s a much different incentive for them to maintain their bridges than municipalities that are often doing it with tax money and often have to make decisions between multiple things where the money goes rather than just bridges and just transportation costs.”

Mr. Lamanna said most inspections are visual, where the inspector will look at the components of the bridge for any signs of obvious degradation or fatigue.

With the bridge in Tempe just inspected weeks ago, what happened between now and then would be determined by investigators. Union Pacific did not have any details on whether the train derailment caused the bridge collapse or vice versa.

“I’m sure NTSB will do a full investigation and they’ll see the previous bridge inspection,” Mr. Lamanna said. “It’s sort of a chicken and the egg thing. Did the train derail and cause the bridge collapse, or was it the other way around? I’m not sure there’s been any video proof or anything of what happened first. But even if it’s a derailment, what caused the derailment? Tracks have been known to buckle in extreme temperatures.”

Mr. Lamanna added that rail bridges tend to be fairly often inspected, with two years being the maximum length of time for inspection of any bridge.

“When they get older, when there’s signs of degradation, that inspection period gets reduced to a year, six months,” Mr. Lamanna said. “Other privately owned bridges such as this one may have a shorter inspection period. It’d be interesting to see what Union Pacific’s alternate route is and how much further the train has to go not having this bridge.”

The Arizona Department of Transportation reported the closure of the Loop 202 Red Mountain Freeway between State Route 143 and Loop 101. The freeway reopened around 1 p.m.

Valley Metro is terminating light rail service eastbound at 38th and Washington streets in Phoenix, and westbound at Smith-Martin/Apache Boulevard in Tempe. Buses are being used to transport passengers around the incident.

Tempe police said to avoid the Tempe Town Lake area for the day as crews worked on the fire. The city of Tempe also canceled all boating activities and classes at the lake.

Agencies from nearby Chandler, Mesa and Scottsdale are helping with the incident, as is the Arizona Department of Public Safety. The Peoria Fire-Medical Department says it sent Fire Boat 199 to the scene after a request by Tempe officials. Peoria’s Station 199 at Lake Pleasant Regional Park is about 56 miles away from the Tempe Town Lake area.

The 2.5-mile Tempe Town Lake is a popular recreation spot for jogging, cycling and boating and close to Arizona State University.

In a statement, Gov. Doug Ducey commended the quick action of first responders and says state agencies are working closely with them.

“Our focus is on protecting public safety and providing any and all resources and assistance necessary to aid Tempe,” he stated. “I’ve also reached out to Tempe Mayor Corey Woods to express the State’s full support in this response.”

Tempe police said there was another derailment in the same area last month that slightly damaged the bridge, but it's unclear if that led to the latest incident.

Union Pacific Railroad officials said 12 cars derailed on June 26 and the repairs were done within 48 hours.

The Associated Press contributed to this report.