Multiple people were displaced after a fire in Duluth early Friday. The Duluth Fire Department says it happened just before 2 a.m. at a duplex on the 300 block of E. 5th St. Crews arrived to find heavy smoke coming from the roof. All occupants from both units had evacuated prior to their arrival. The department says crews attacked the main body of fire in the upstairs unit. They remained on scene for just over three hours to remove smoldering insulation from the attic space. No one was injured. The Duluth Fire Marshal's office investigated the fire and the cause was determined to be accidental-electrical in nature. Initial damage estimates are at $30,000 for the structure and $20,000 for contents. The American Red Cross is assisting with two of the residents displaced. The department says the other tenants in the duplex are staying with family.