Officials in Tacoma, WA, say they have a poor-quality security camera video of last Saturday’s propane explosion at a foundry.

Despite the low quality, the News Tribune reports investigators could see trucker Charles McDonald apparently struggling to connect a hose to a stationary tank.

Then, McDonald “disappeared in a cloud” of released propane, the News Tribune reported. McDonald was critically injured in the blast.

The gas was ignited by a foundry furnace, the News Tribune reported.