Kuehne and Nagel, the company that operates the site, helps Amazon ship extra-large items to customers, according to Amazon.

By about 9:15 a.m., there were still active flames at the building, and firefighters remained in a defensive position, battling the blaze from outside, Baker said.

“But it’s certainly a lot more controlled than it was earlier this morning,” he said.

Officials remained concerned about the building’s structural integrity, and firefighters were keeping a safe distance in case any more walls collapsed.

“I would estimate it’s going to be a total loss,” Baker said of the building.

It was not immediately clear what caused the fire.

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

No nearby Amazon sites were affected by the fire, and the company expects the blaze to have minimal impact on customers. Orders will be fulfilled from other locations, the company said.

The blaze prompted officials to close the 10 Freeway in both directions for more than an hour. The freeway reopened shortly after 7 a.m.