Truck that caught fire, exploded on I-5 in Seattle was carrying oxygen, propane and more

ByShannon J. Cortes

Jul 28, 2022

The southbound lanes of Interstate 5 closed Thursday afternoon at Downtown Seattle after a welding vehicle caught fire and began to explode. After a shutdown of several hours, the highway reopened.

According to the Seattle Fire Department, no injuries were reported. It was too early to know what caused the fire, but officials said they suspected a possible maintenance issue with the truck itself.

All lanes were closed around 1:30 p.m. between Mercer and State Route 520. Around 2:30 p.m., northbound lanes reopened.

The express lanes were closed for several hours but have since reopened to allow southbound traffic to pass through downtown Seattle.

Photo credit: Robert Galvin

Authorities said Friday it was a welding truck carrying oxygen, acetylene, propane and an argon cylinder that caught fire. Explosions could be observed for at least 30 minutes.

Shortly before 4:30 p.m., firefighters said the fire was out.

Officials informed residents living near I-5 at Lakeview Blvd. E to close their windows and doors to avoid being exposed to toxic smoke from the fire.

The Mercer Street exit sign was charred and burned and had to be taken down.

The roadway was also damaged, but it was deemed safe enough for drivers to use.

“We had a bit of a burn in the concrete and it’s called rolling work. Just kind of a layer is coming off and so we have to put some asphalt on it as a temporary patch and then we’ll come back later on a program scheduled evening to make a more permanent solution,” said Washington State Department of Transportation spokesman Tom Pearce.

But that was only a temporary fix – WSDOT says some of the concrete may have come loose and work will be scheduled for a more permanent solution.

Pearce said it would happen in the middle of the night when it affected fewer people.

Editor’s note: An earlier version of this story stated that the tanks contained liquid oxygen, as first reported by the Seattle Fire Department. On Friday, the department issued a correction stating that “the truck that caught fire was a welding equipment delivery truck carrying oxygen, acetylene and propane, as well as an argon cylinder. The oxygen was not liquid”. The story has been updated.