Lightning is the prime suspect behind an overnight house fire in south Minneapolis.

The blaze started shortly before 1 a.m. Tuesday at a home in the 3700 block of Pleasant Avenue S., said Assistant Fire Chief Bryan Tyner.

The family, two adults and two children, escaped unharmed, Tyner said.

“There was fire showing through the roof” when fire crews arrived, Tyner said. By 1:30 a.m., the blaze was considered under control, he added.

While it’s too early for an official determination on how the fire started, Tyner said that “lightning certainly fits the profile” in this case.