State fire investigators are trying to determine the cause of an overnight fire that severely damaged a child care center in Brooklyn Park.

Firefighters from multiple agencies were called to the Xerxes Avenue KinderCare on the 7900 block of N. Xerxes Avenue about 2 a.m. Thursday after a smoke alarm went off.

Crews arrived to find heavy smoke and flames shooting through the roof, said Camille Hepola, a spokeswoman for the Brooklyn Park Fire Department.

No one was in the building at the time of the fire, which grew to two alarms, Hepola said. No firefighters were hurt battling the blaze that was put out several hours later.

The building was declared a total loss, Hepola said.

"With the COVID-19 crisis and school closures, many day care facilities and schools are staying open to help take care of children of first responders and health care professionals," Hepola said. "This is very unfortunate for those individuals who relied on this care."

Fifteen-year-old Alyssa Deason and her family stopped by Thursday morning to see the remnants of the school where she attended kindergarten through third grade. It's where she learned to read and where her 8-year-old sister Isabelle Rapke attended as well.

"I spent a lot of my younger childhood at this day care, and I got to know the workers pretty well," Deadon said. "I made a lot of memories here and it's kind of sad to see all of this come down in just a matter of, you know, 30 minutes or so at night. But I know the staff that worked here was amazing and I know that there's a lot of strong people there that they can hopefully try to rebuild it."

Brooklyn Park Fire Deputy Chief Todd Seitz said the cause is under investigation by state fire marshal.

Seitz said when fire crews arrived on the scene heavy smoke and fire erupted from the building.

"It wasn't long before we had fire coming through the roof of the building and had to go defensive on it. So I ended up using three aerial trucks," Seitz said.

Firefighters from West Metro, Fridley, Coon Rapids, Plymouth and Brooklyn Center departments assisted with the effort to douse the flames.

Seitz said the fire marshal has been in contact with the owners. KinderCare facilities management is on scene assessing the damage.

"I'm sure it's going to have an impact. I don't know how many kids came here but they're going to have to figure out alternatives," Seitz said.