Two structure fires kept firefighters busy for several hours on a frigid night in north Minneapolis before being brought under control late Wednesday.

No injuries were reported in the blazes, both of which featured flames that could be spotted from a distance.

The first fire, at a one-and-half-story residence in the 3600 block of N. Emerson Avenue, was “fully involved” at about 8 p.m., the Fire Department said in one of several tweets. After knocking down flames on the first floor, firefighters battled fire in the attic and roof before declaring things under control about 11 p.m.

Even as that fire burned, fire trucks were called to another blaze at a two-story duplex in the 4800 block of N. Lyndale Avenue. Firefighters continued to pour water onto that blaze, which had collapsed the building’s roof and was bowing its walls, for a couple of hours. Around 10:45 p.m., the department said on Twitter that that fire was under control.

The cause of both blazes remains under investigation.