Firefighters spent several hours Wednesday putting out flames and lingering hotspots, and the water flooded the building's bottom floor. Crews pumped water from lower-level apartments Thursday.
Police also were trying to determine whether there's a connection between the blaze and a reported sexual assault a few hours earlier in one of the apartments.
"At this point, we're gathering more evidence and information," Simms said. "So, we're hoping to have closure to this whole case very shortly. We're working closely with different units in the Detroit Police Department to connect other crimes to this fire."