WILLOUGHBY, Ohio (WJW) — Investigators are trying to figure out what touched off a fire that destroyed a huge Willoughby apartment building that was under construction. 

Nearly 20 crews responded to the scene of a large fire at the complex in Willoughby Friday morning just before 6 a.m., according to Willoughby Fire Chief Todd Ungar.

The fire was at the Chagrin Riverwalk complex on Mentor Avenue between Erie Street and Kirtland Road.

Ungar said no one was inside the building when the fire started. He said the fire was found throughout the building.

Ungar said their main concern was making sure the surrounding buildings didn’t catch fire.

High winds made things worse as the heat melted siding on nearby buildings. FOX 8 Weather reported powerful wind gusts throughout the day.

More than 20 cars in a nearby parking lot were damaged or destroyed.

“The fire was coming across the street, you can see the smoke in the background. It was drifting across the street. It’s high winds, it’s a wind-driven fire. The entire street was fire.”

Ungar told Fox 8 crews that it is hard to tell at this point what exactly started the fire in the four-story apartment building.

“Because the building is under construction it’s hard to tell what exactly started the fire. The fortunate part about it is that nobody was inside the building at the time of the fire,” Ungar said.

Ungar did say buildings in that area were evacuated and people who were in nearby apartments were moved to the complex’s community center.

“Please use caution and an alternate route,” the Lake County Sheriff’s Office Sheriff Frank Leonbruno Facebook page says.

Willoughby Fine Arts did close for the day. Andrew Osbourne Academy was also advised to close down.