Shortly before 5 a.m. on Tuesday, crews from several agencies were called to the 400 block of East Patrick Street, where smoke was billowing from a three-story building, officials say.
Firefighters then searched the building and saved three people who were trapped on the third floor.
A second alarm was called after the initial save, sending additional crews to assist in knocking down the flames and extinguishing the fire, according to a spokesperson for the Frederick County Sheriff's Office.
One person inside was taken to be treated for minor injuries at Frederick Health Hospital. The other two left the scene on their own without being treated.
In total, around 75 firefighters took less than a half hour to get the fire under control, with crews staying at the scene for several hours to clean up potential flare-ups as they investigate the cause of the fire.
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