A six-alarm inferno ripped through a California warehouse early Tuesday morning, with authorities taking an employee into custody, as reported by FOX 11.

Videos captured at the scene depicted flames engulfing the roof of the Kimberly-Clark consumer goods facility in southern Ontario, California, while plumes of smoke filled the night sky.

Emergency crews were dispatched around 12:30 a.m. to the sprawling 1.2 million-square-foot warehouse. Upon arrival, they found the roof already ablaze, according to KTLA.

The dramatic scene unfolded as a six-alarm fire consumed the Kimberly-Clark warehouse in Ontario, California, on April 7, 2026, with firefighters tackling what is believed to be an arson-induced blaze. (KTTV)

The San Bernardino County Fire Department confirmed that the Ontario Fire Department was leading efforts to contain the six-alarm fire, which involved paper products, with support from several nearby agencies. Police deployed drones to provide aerial support for the operation.

The warehouse, filled with paper products like tissues and other consumer items, contributed to the rapid spread of the fire, FOX 11 noted.

Firefighters battle a massive six-alarm blaze at a Kimberly-Clark warehouse in Ontario, California, on April 7, 2026, after authorities said the fire was intentionally set. (KTTV)

By about 5 a.m., firefighters shifted to a defensive strategy, positioning ladder trucks around the building and dousing the structure from above as the hours-long fire continued to burn, KTLA reported.

About 20 employees were inside the warehouse when the fire broke out, but all escaped without injury, according to FOX 11.

Ontario Fire Department Deputy Chief Mike Wedell said that while the building’s internal sprinkler system was operational, the fire grew “exponentially very quickly,” forcing initial interior crews to retreat and adopt a defensive strategy, FOX 11 reported.

Firefighters battle a massive six-alarm blaze at a Kimberly-Clark warehouse in Ontario, California, on April 7, 2026, after authorities said the fire was intentionally set. (KTTV)

Fire officials said the incident is being investigated as an arson case and that one suspect is in custody, the outlet reported.

“At this point, we do have a subject of interest,” Ontario Fire Department Deputy Chief Mike Woodell told KTLA. “That individual has been brought into custody, arrested, and taken to the police department. The individual is awaiting questioning by Ontario Police Department detectives who are en route.”

Fox News Digital reached out to Ontario’s police and fire departments for comment.