A fire heavily damaged a building that houses a Somali-American restaurant and several apartments Friday morning in the Cedar-Riverside neighborhood in Minneapolis.

Firefighting crews arrived in the 600 block of S. Cedar Avenue just after 5 a.m. to find flames shooting out of an exterior grease vent of the Maashaa'allah Restaurant, authorities said.

Firefighters entered the two-story structure and found that the blaze had spread into the ceiling, the walls and an interior grease chute in the restaurant's kitchen.

Flames also spread into a second-floor hallway above the kitchen, said Melanie Rucker, the Minneapolis Fire Department's assistant chief of administration, in a news release.

Residents of the apartment units above the restaurant escaped unharmed, and no one else was found inside as firefighters searched the building, Rucker said.

The building was deemed uninhabitable, Rucker said.

The cause of the fire remains under investigation.