Milwaukee Fire Department is calling a fire on the city's south side suspicious. 

The fire happened on S. 15th Place and W. Grant Street Saturday afternoon. Bat. Chief Sean Slowey said the burn patterns on the bottom and near a door from inside the home are leading investigators to believe someone caused the fire. 

"For fire to be on the bottom of a door means there had to be fire under the door and the only thing that could be that low to the ground is carpeting or a flammable liquid," Bat. Chief Slowey said. 

However, Bat. Chief Slowey said carpet fires are uncommon. He said they are typically caused by extension cords under the carpet, but fire crews did not find any wires by the door Saturday. 

The fire is still under investigation. The American Red Cross is assisting the family who lived in the home.