As firefighters continue battling a five-alarm fire at an unfinished apartment building, the University of Maryland’s College Park campus is closed and students who remain on the grounds have been told to stay inside with windows and doors closed.

The blaze broke out around 9:30 a.m. on the upper levels of Fuse 47, a huge, mixed-use development that has been under construction in the 4700 block of Berwyn House Road.

More than 200 firefighters were called to the scene, where units found heavy fire on the fifth and sixth floors, according to Prince George’s County Fire Chief Ben Barksdale. One firefighter has sustained a minor injury.

The fire is largely under control at this point, but hot spots remain and PGFD will likely remain on the site until well into the evening. Public Information Officer Mark Brady said it may be the largest fire suppression effort in the county’s history.

A confluence of factors is making it more difficult to fight the fire and exacerbating the effects on the neighborhood.

Because the development was still under construction, Barksdale said at an afternoon press conference, there’s a lot of wood around the site and plenty of “void spaces that that fire was able to get to and travel throughout the building.” Since the building was unoccupied, the fire suppression system wasn’t full operational. The location, backing up to residential units without street access, and the design, with a courtyard in the middle, have also made access to much of the structure difficult for firefighters.

Meanwhile, the atmospheric conditions are allowing the plumes of smoke to linger. “We’re doing the best we can,” Barksdale said. “With today’s weather, the smoke is laying low.” He recommended that neighbors stay inside and turn off HVAC units.

About 65 senior citizens at a nearby facility were evacuated and taken to a community center. Officials shuttered the University of Maryland’s College Park campus at 1 p.m. And people as far as three miles away report smelling smoke.

Investigators are on the scene, but officials do not yet have a suspected cause.