What started as a routine vehicle fire call in unincorporated Arapahoe County quickly turned into a hazmat situation on Wednesday after firefighters discovered a leaking liquid oxygen tank inside a commercial box truck.
South Metro Fire Rescue crews were dispatched to the area of E. Harvard Avenue and S. Trenton Way for the reported vehicle fire. When Engine 21 arrived, firefighters found the box truck with a liquid oxygen tank leaking inside the cargo area, and the incident was upgraded to a hazardous-materials response. Crews isolated a valve on the tank to slow the leak, secured the area while special-operations units were requested, and ultimately turned the truck over to the Arapahoe County Sheriff's Office for removal. No injuries were reported.
According to South Metro Fire Rescue, Engine 21 located the truck and requested the district's HazMat team after spotting the leaking liquid oxygen tank. The agency's post explains that crews isolated a valve on the tank to mitigate the hazard and that the call was reclassified as a hazardous-materials incident. South Metro said the scene was later handed over to the Arapahoe County Sheriff's Office so the vehicle could be removed.
Why Liquid Oxygen Raises The Stakes
Liquid oxygen is a cryogenic oxidizer, which means it does not burn by itself but can sharply accelerate combustion and create oxygen-enriched atmospheres that pose serious risks to anyone nearby, including first responders. The Pipeline and Hazardous Materials Safety Administration classifies refrigerated liquid oxygen as UN1073 and spells out specific rules for shipping and handling cryogenic oxygen.
Safety guidance from Lawrence Berkeley National Laboratory warns that liquid oxygen can cause severe cold burns on contact and that oxygen-contaminated materials may ignite without warning, which is why even a slow leak gets taken seriously.
How Crews Handled The Scene
South Metro's Special Operations page notes that its HazMat and technical-rescue teams are trained for tasks like valve isolation, atmosphere monitoring and tight scene control. Those routine tactics line up with what happened here, where firefighters worked to isolate the tank valve and clear the immediate area before handing things off for the truck's removal.
Similar Calls Around The Country
Incidents involving liquid oxygen have triggered full-scale HazMat responses elsewhere as well. On July 7, a tanker fire on Manhattan's East Side sent thick vapor into the air and prompted evacuations near several major hospitals. CBS New York reported that FDNY and HazMat units checked surrounding buildings and that no injuries were initially reported.
In the Arapahoe County incident, South Metro said no injuries were reported and did not release further details about the box truck or its operator. For non-emergency questions, the department directs people to its contact page, which lists administrative and public information numbers.
