A massive six-alarm fire engulfed a 1.2-million-square-foot Kimberly-Clark paper products warehouse in Ontario, California, early Tuesday, April 7, 2026. Firefighters were forced to retreat as the blaze collapsed the warehouse roof and overwhelmed initial response efforts. One suspect is in custody, and authorities are investigating the fire as a suspected case of arson.
Immediate Action & Core Facts
The fire broke out around 12:30 a.m. at the facility located at South Hellman Avenue and Merrill Avenue. About 20 employees were inside the building at the time but escaped without injury. Firefighters initially attempted to battle the flames but were forced to adopt a defensive strategy as the fire grew "exponentially," according to Ontario Fire Department Deputy Chief Mike Wedell. The blaze was still burning as of 6:30 a.m., with visible smoke plumes and flames seen for miles.
Deeper Dive & Context
Firefighting Efforts and Structural Damage
Fire crews pumped 1,000 gallons of water per minute to contain the blaze, but the fire's rapid spread forced them to retreat. The warehouse's internal sprinkler system was operational but proved insufficient to control the flames. By 5 a.m., firefighters shifted to a defensive strategy, using ladder trucks to douse the structure from above.
Investigation and Suspect Detention
Authorities confirmed that one person was taken into custody and is being treated as a suspect in the arson investigation. No additional details about the suspect or potential motives have been released. The Ontario Fire Department and San Bernardino County Fire are leading the investigation, with assistance from neighboring agencies.
Impact and Response
The fire caused significant structural damage, including the collapse of the warehouse roof. The facility produced paper products such as tissues and other consumer goods, which contributed to the fire's rapid spread. Fire officials expect the scene to remain active for the rest of the day.
Public and Official Reactions
No official statements from Kimberly-Clark or local government leaders have been reported. The Ontario Fire Department emphasized the danger posed by the fire and the necessity of the operational retreat to ensure firefighter safety.