A tank containing diesel fuel has exploded during maintenance work at Marathon Detroit Refinery, forcing a mandatory evacuation order for a nearby area. One employee has been injured in the blast, authorities said.

Reports of the explosion and fire came in just before 6 pm local time.

Authorities on the ground say the explosion injured an employee. The incident occurred during a maintenance check.

Marathon spokesman Shane Pochard tells the Detroit Free Press the small fire Wednesday morning was extinguished quickly and the worker had minor injuries.

The adjacent city of Melvindale however ordered a partial evacuation due to concerns over air quality from the fire rise. State police also closed ramps from I-75 to Schaefer in both directions.

“Police have blocked Fort Street off by I-75 south … oh my goodness … there’s an ambulance out here, a fireman standing outside, you know, it doesn’t look like they are trying to get close. They are not trying to go in there,” one listener told the local radio station.

A witness, Dan Taylor told the Detroit News that “I saw the fire ball. The whole top of the tank was on fire and you could see it melted.”

The fire erupted in one of the refinery’s smaller tanks, Pochard told the Detroit Free Press.

Marathon’s own fire crew were battling the flames, along with first responders from Detroit and surrounding areas. At least two trucks at the scene were streaming water and two trucks were streaming foam.

A HazMat team from the Detroit Fire Department and Senior Fire Chief Carl Smith were at the scene as well. The fire was extinguished just before 8 pm local time.

About 300 Marathon employees and additional 300-400 contractors work at the refinery, Peter Brokas, the head of security told the Detroit Free Press.

(Watch the video posted on YouTube by KryssisKornerDetroit)