NEW YORK — At least 18 firefighters and three civilians were injured when a 7-alarm fire swept through a parking garage in Brooklyn on Monday morning, authorities said. None of the injuries were considered life-threatening.

FDNY Commissioner Daniel Nigro said those injured suffered smoke inhalation and heat exhaustion.

The fire broke out at around 9 a.m., destroying multiple cars at the King's Plaza Shopping Center in the Mill Basin neighborhood around 9 a.m., CBS New York reports. Plumes of smoke could be seen pouring from the structure. Officials warned residents with heart or lung conditions to avoid the area.

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Kings Plaza mall, which opens at 10 a.m., shut down as the fire and smoke spread. The mall tweeted that customers should avoid the area

King's Plaza mall shut down as the fire and smoke spread. The mall said on Twitter patrons should avoid the area.

Some 250-300 firefighters responded to the blaze, Nigro said. The garage is being checked for possible structural damage. The cause of the fire is under investigation.

"Any time you have a car fire, you're likely to have certainly tires explode," Nigro said. "And much of what (witnesses) heard were tires on these multiple vehicles exploding many times. Very dangerous for our members, and for anybody nearby."