A fire Saturday afternoon at a duplex in northern Lawrence displaced a family of four.

Division Chief Eve Tolefree, a Lawrence Douglas County Fire Medical spokeswoman, said Monday investigators were still trying to determine the cause of the fire and amount of damage at 319 Northwood Lane, but a preliminary investigation indicated it started after charcoal briquettes weren’t discarded properly.

Firefighters said Saturday the fire started in the garage and damaged the inside of the duplex. No one was injured.

Jane Blocher, executive director of the Douglas County chapter of the American Red Cross, said the chapter provided food and clothing to one family at the duplex. They are staying temporarily with family members. Blocher said residents living on the other side of the duplex were not home during the fire, and the Red Cross has not received calls to assist them.

Tolefree said Monday investigators were also still trying to determine the cause and damage estimate of a separate northern Lawrence fire earlier Saturday at a shed at 1300 W. Second Terrace. That fire damaged the exterior of a home on the property.