Fire investigators are trying to determine what sparked the blaze that struck a multi-story building in downtown Waterloo. The fire apparently started in the lobby of the 4th floor of the Russell-Lamson Building about 11:30 last night. No injuries are reported. There’s no damage estimate. The Hawkeye chapter of the American Red Cross is helping nine residents with food, clothing and shelter. The building has several floors of apartments in addition to a restaurant and several businesses on the main floor.