ST. LOUIS – A large fire broke out late Saturday evening at an abandoned warehouse in St. Louis, just a little north of downtown. No one is hurt despite the scare.

The fire intensified around 8:30 p.m. Saturday at the warehouse near North Seventh and O’Fallon streets. Officials tell FOX 2 the building was a former timber construction site in the Columbus Square neighborhood.

Many around St. Louis noticed thick smoke in the sky around 8 p.m. Some noticed it miles away from the city. Fire crews initially responded to the smoke and reported moderate smoke conditions from one corner of the building.

Dennis Jenkerson, commissioner of the St. Louis Fire Department, tells FOX 2 that firefighters were preparing to potentially enter the building when suddenly the second floor went up in massive flames. No one was inside as massive flames broke out in the top floor.

“It was a little concerning as quickly as this building took off,” said Jenkerson. “It was more concerning because our firefighters could’ve been inside this building. A minute even inside [for the firefighters], this could have had a different outcome.”

Fire crews are responding to a large warehouse fire Saturday evening in St. Louis, just a little north of downtown. (Photo courtesy: Mary Scott/FOX 2)

It remains unclear what exactly caused the fire at this time. Jenkerson said it does appear a little suspicious, but St. Louis fire investigators are working to determine what happened.

“”It’s one of those things we’re going to take a hard look at,” said Jenkerson. “They thought they had a small fire within one corner of the building, and within seconds, the entire second floor was engulfed.”

The St. Louis Fire Department immediately called for a third-alarm response after the massive flames emerged. The fire is considered under control as of 10 p.m. Saturday.

Jenkerson says around 85 firefighters responded to the scene, using four aerial devices and three ground monitors in efforts to put out the fire. With swift response, crews prevented the fire from spreading to other vacant buildings around the area.

“Firefighters did a great job,” said Jenkerson. “It’s been a busy day for the St. Louis Fire Department.”

There are on injuries or inhalation concerns, but the fire has led to some scattered debris around the ground.