Authorities said two workers at the University of Maryland College Park suffered injuries Monday from a flash fire after they had worked on a malfunctioning heating and air conditioning unit on the roof of a dorm.

One of the workers suffered injuries that were serious but not life-threatening and was taken to a trauma center, according to Prince George’s County spokesman Mark Brady. The worker’s injuries involved “serious trauma to the upper body,” according to Brady.

The second person sustained “less serious injuries,” Brady said, and was taken to an area hospital.

The incident was reported at 9 a.m. on social media outlets of the university police and Prince George’s County fire officials. Police evacuated the area and warned people to stay away. Oakland Hall, the nine-story dorm where the incident occurred, is home to about 700 students, according to the university’s Web site.

Police at the University of Maryland said in a Twitter message just after 9 a.m. that “preliminary indications are a HVAC unit caught fire on top of Oakland Hall. Fire is out.”

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