Report Outlines Factors in AZ Battery Blast Injuring Eight FFs

July 28, 2020
Firefighters weren't clearly told of the dangers connected to facilities that house large batteries used to power communities, according to a report about an explosion at a Surprise site in 2019.

An "insufficient understanding" of the dangers associated with a battery site used to power an Arizona community was one of five factors that hindered the response to an explosion that injured eight firefighters and a police officer, according to a new report about the 2019 incident.

The explosion happened in April 2019 at Arizona Public Service's McMicken energy storage facility in Surprise, where large lithium batteries are used to store and distribute solar energy. Four Peoria firefighters were seriously injured in the blast, and a captain is still recovering from the incident, KNXV-TV reports. Four Surprise firefighters and a city police officer also were evaluated for less serious injuries.

The nearly 80 page report, which was released Monday, was put together by DNV GL Energy Insights USA for APS. It drew its conclusions and recommendations based on information about the batteries, the facility and firefighters procedures.

"We see this as clearly a tragic equipment failure," Jacob Tetlow, senior vice president operations for APS, told The Arizona Republic. "We deeply regret the injuries to first responders. Our thoughts have certainly been with the first responders throughout the investigation."

Along with pointing to no response plan for dealing with the malfunctioning battery, the report outlined four other areas to led to the incident, according to KNXV:

  • A "thermal runaway event" was created by the "internal failure" of the malfunctioning battery
  • The facility's fire suppression system was unable to handle putting out the "thermal runaway event"
  • A cascade effect resulted because of no "thermal barriers" between batteries
  • No ventilation for concentrated, flammable off-gases

"Just as the lack of information during the design and build phases of the project contributed to the event, so, too, did the lack of real-time situational awareness during the emergency response," the report stated.

Surprise Battalion Chief Julie Moore, who was part of the 2019 response, agreed that firefighters weren't given enough information about the dangers that can surround such a battery sites. 

"We did the best we could," she told KNVX. "We had two hazmat teams on scene."

Since the incident, new safety protocols have been set up to "better address hazard assessment and training for first responders," according to the report. Despite these safety improvements, even more can be done to prevent such an event happening again, the report added.

APS has plans to build more battery sites across Arizona in the coming years.