A six-alarm fire engulfed a 1.2 million-square-foot Kimberly-Clark warehouse in Ontario, California, early Tuesday morning, forcing firefighters to evacuate the area as flames consumed the massive facility.

The blaze ripped through the warehouse structure, creating dangerous conditions that required emergency responders to retreat from their firefighting efforts. The scale of the fire prompted authorities to escalate the response to a six-alarm level, indicating the severity and size of the incident.

Authorities have arrested an employee of the facility in connection with the fire. The individual is being held as a suspect in what investigators are treating as a potential arson case. No details have been released regarding the employee's identity or specific charges.

The Kimberly-Clark facility, which spans over one million square feet, represents a significant industrial presence in the Ontario area. The company is known for manufacturing consumer paper products and personal care items.

Investigators are working to determine the exact cause of the fire and the circumstances surrounding the employee's arrest. The incident caused significant disruption to the surrounding area as emergency crews worked to contain the massive blaze.