A woman caused a fatal car crash in Utah because she was too busy watching porn while driving … according to authorities.

Multiple outlets report that 44-year-old California woman Christine Chao was charged Tuesday with automobile homicide in connection with the deadly June 12 crash.

According to charging documents … Chao “told officers she was at fault” … and when investigators got a warrant to search her phone, they found she’d accessed a porn site “less than two minutes before the crash.”

The charging docs say Chao was driving on I-15 when she crashed into a white sedan, which had slowed down in a construction zone.

The sedan then hit the SUV driving in front of it, and all three vehicles went off the road.

KSLreports that 66-year-old Utah man Scott LaVar Lichfield — who was riding in the backseat of one of the cars in the crash — suffered a head injury in the accident and later died.