Twelve adults and 12 children fled their 2 1/2 story duplex in north Minneapolis after a fire broke out shortly after midnight on Tuesday.

The Red Cross had been called in to help the 24 residents at the duplex on the 1600 block of Hillside Avenue North, said Minneapolis Assistant Chief Cherie Penn.

The fire began in the basement and spread to the first, second and third floor of the building, she said. There were no injuries to the residents, but one firefighter sustained a knee injury and was transported to Hennepin County Medical Center where she was treated and released, Penn said.

The first alarm fire, reported at 12:21 a.m., brought out six fire apparatus and 20 to 25 firefighters, she said. The cause of the fire is under investigation, Penn said.

Lynnette Nyman, a spokesperson for the American Red Cross in Minneapolis, said the 24 displaced people were related to each other. She said her organization was putting them up in a local motel and providing them with food and clothing.