HARTLAND, Wis. (WLS) -- Police have launched a criminal investigation after an early morning apartment fire in Hartland, Wisconsin left six people dead Friday.
Aerial footage showed fire and smoke damage, as well as some exterior bricks on the ground outside the four-family complex.
"I smelled smoke, and a neighbor of mine heard a big boom, and he said something blew up, so we're not sure what blew up," neighbor Tracy Marinello told WISN. "He did say some people did not make it out."
Police said they are now looking into whether the fire was intentionally set. Police said it was too soon to say definitively if all of the deaths were fire related.
Authorities clarified the number of fatalities Friday afternoon after it was originally reported that seven people had died. Police have not released the names or ages of the victims.
Hartland has a population of 9,000 residents and is in Waukesha County, about 26 miles west of Milwaukee.