Two employees were severely injured early Tuesday morning after a 7,000 gallon oil tanker caught fire at a used oil recycling facility near 24th Street and Jefferson. Phoenix Fire officials believe the employees were filling a truck with used motor oil when the fire occurred.

They were taken to the Maricopa Medical Center, but hospital spokesman Michael Murphy said due to the nature of the burns, they could not immediately be taken in for surgery.

"When they arrived at the Maricopa Medical Center we had to decontaminate them," Murphy said "They were covered in oil — diesel oil and motor oil."

The victims are now undergoing treatment at the burn center. One is a 23-year-old man with second and third degree burns. The other is a 45-year-old man, also with third degree burns. Both are in critical condition.

The Arizona Department for Environmental Quality is now turning its attention to the water runoff from fire crews. Spokesman Mark Shaffer said an investigation is underway to determine how far the oil and water mixture has gone.

"That water is contaminated from the oil product and all that, and it goes down into the storm drains of the city of Phoenix," Shaffer said. "So we’re trying to keep the pollution from going into the stream beds."

Shaffer doubts the water has reached the Salt River but says it could still get into groundwater. The facility, owned by Fuels, LLC, passed its last routine inspections, and it is still unclear what caused the fire.