Several businesses at a Lake City strip mall were destroyed in a quick-moving blaze Monday night that has since been ruled an arson.

A man called 911 shortly before 11 p.m. and reported that several people had broken into businesses in a shopping center near the intersection of 30th Avenue Northeast and Northeast 127th Street, according to Seattle police. As the witness was still on the line with a dispatcher, he watched the people leave in a vehicle and said the business they had burglarized was on fire, says an item posted on the Seattle Police Department’s online blotter.

The fire was well involved when the first Seattle Fire Department (SFD) crews arrived, and heavy smoke was pouring from a small void space connecting all the businesses in between the ceiling and the roof, according to a post on the department’s blog.

By 11:01 p.m., the blaze had spread through the entire building and firefighters switched to a defensive strategy, pouring water on the fire from outside because it was deemed too dangerous for them to go inside, the blog post says. The building’s roof partially collapsed 30 minutes after the fire started.

It took nearly an hour after that to bring the fire under control, with 84 firefighters responding to the scene, according to the SFD blog.

No injuries were reported.

The blaze caused an estimated $2.7 million in damage, SFD said on Twitter on Tuesday afternoon.

Businesses in the center included Papa Murphy’s Pizza, Swan Massage & Spa, Aloha Ramen, Teriyaki Time, a laundromat and a discount store. The fire department said all eight units in the strip mall, including seven businesses and a vacant space, were deemed a total loss.

The Seattle Police Department’s Arson and Bomb Squad is leading the investigation.