REDLANDS (CBSLA) – Investigators are trying to determined what caused a three-alarm blaze which tore through an Amazon Distribution Center in Redlands early Friday morning while employees were working inside. Fortunately, no one was hurt.

June 5, 2020. (CBSLA)

READ MORE: Body Discovered In Vehicle In Silver Lake

The blaze was reported at 5:30 a.m. at 2255 West Lugonia Ave., in the area of the 10 Freeway and Mountain View Avenue.

Video from the scene showed huge flames and plumes of black smoke shooting hundreds of feet into the air. There were several Amazon big rigs parked outside which also caught fire.

“All I could hear is my supervisors yelling, ‘Fire,’ and ‘Get out of the building as fast as you can,'” employee Aquila Canteen told CBSLA. “And all I could see was people scattering.”

There were about 40 employees inside when the fire broke out.

“Within 15 minutes the whole back of the building collapsed and exploded,” Canteen said.

In a statement to CBSLA, Amazon said the warehouse is operated by a third-party company called Kuehne and Nagel which specifically helps Amazon ship very large items.

“We are glad everyone is safe, and thankful for the efforts of the local firefighters and first responders,” Amazon wrote. “This site was operated by a third party and we will support them throughout this process.”

READ MORE: Arnold Schwarzenegger Involved In Car Crash On Sunset Boulevard That Sent 1 To Hospital

June 5, 2020. (CBSLA)

The fire was brought under control by 11 a.m., but crews with the Redlands and San Bernardino County firefighters remained on scene dousing hot spots.

Investigators were collecting security video from inside the store to try and determine what caused the blaze. Kuehne and Nagel workers told CBSLA they are not allowed to store combustible items in the building.

One employee told CBSLA that he didn’t see sprinklers or hear any fire alarms.

“I didn’t hear no fire alarms, I didn’t see no fire sprinklers, nothing,” employee Chris Smith said.

“That is highly concerning, we’re looking at a modern building with the latest advances installed inside the building regarding fire protection systems,” Redlands Fire Chief Jim Topoleski told CBSLA. “It’s highly concerning, that’s why we’re bringing in outside resources to help us look at the cause and origin.”

Topoeski also called the speed at which the fire spread in a building larger than 300,000 square-feet “highly unusual.” It’s also unclear if the fire is linked to a second three-alarm fire which occurred at Splash Kingdom Waterpark early last month.

MORE NEWS: High-Powered Winds Whip Through Southland, Bringing Damage To Houses, Trees

The 10 Freeway was shut down in both directions for several hours, but has since reopened. Amazon expected “minimal” impact to customer orders from the incident.