What was initially reported by the University of Maryland as an explosion, turned out to be a malfunctioning heating and air conditioning unit.

WASHINGTON – Two workers have been injured after a flash fire on the roof of a University of Maryland at College Park dorm, according to Prince George’s County Fire and EMS.

The university initially sent an alert that there had been an explosion on the roof of Oakland Hall, a nine-story dorm. Students were told to evacuate immediately and to stay away from the area.

The university has since followed up with this alert:

Update from incident at Oakland Hall: There was no explosion. A malfunctioning AC Unit caught fire. The fire is out. Units are clearing.

Prince George’s County Fire and EMS spokesman Mark Brady says the pair was working on a heating and air conditioning unit on the roof of Oakland Hall on Monday morning when the fire occurred, accompanied by a blast.

He says no fire was evident by the time fire fighters arrived.

According to tweets from Mark Brady, the spokesman for the fire department, one of the workers who was working on the HVAC system, was seriously injured. The injuries are not life-threatening.

Brady says one worker was taken to a hospital in serious condition with possible burns and lacerations that were not considered life-threatening and the other had minor injuries.

Brady says no students were injured. Most students are currently on winter break until the spring term begins later this month.

UPDATE-UofM-2 workers, not students injured after a flash fire while working on a HVAC roof unit. 1 worker serious NLT inj TX to trauma cntr — Mark Brady (@PGFDPIO) January 13, 2014

UPDATE – U of M – preliminary reports of an HVAC flash fire. 2 people injured. Any fire is reported out. Injured are with @UMPD — Mark Brady (@PGFDPIO) January 13, 2014

some kind of transformer or HVAC unit burst and poss. burned on the roof of Oakland Hall in #CollegePark pic.twitter.com/HMkA21Fdln — Brad Freitas (@NewsChopperBrad) January 13, 2014

The Associated Press contributed to this story. Follow @WTOP on Twitter.