Arson investigators have found that a Minneapolis fire that killed six people was not suspicious, but officials say they will likely never know exactly what started the blaze.
The April 2 fire in the apartments above McMahon's Pub on Lake Street killed three children and three adults. It was the deadliest fire in Minneapolis since 1986.
The joint Arson Unit of the Minneapolis Police and Fire departments announced Tuesday that investigators have ruled out suspicious causes, but have not been able to pinpoint the cause of the fire. Fire officials say the official cause will be labeled "undetermined."
Police officials say that the finding is not unusual. Last year, about 23 percent of investigations into structure fires in Minneapolis resulted in an "undetermined" ruling.
"The fire destroys the evidence that we need to make that call," said Minneapolis police spokesman Sgt. William Palmer. "It's very unlikely that we will ever know exactly what started this fire."
The finding means that although the active investigation has concluded, the case will remain open.