A charter bus carrying around 30 people heading north to Washington on Highway 99 crashed when the bus crossed the centerline impaling itself on a highway pole at an exit near Livingston in Merced County at around 3:25 a.m. Pacific time. The accident resulted in four fatalities (earlier reports of five fatalities proved to be incorrect) with seven more suffering major injuries.

As of Wednesday, officials had not determined what caused Tuesday accident. Highway patrol officer on the scene, Moises Onsurez stated that “The pole went through the center of the bus, and that’s where the injuries were sustained,” Police had not had an opportunity to speak to the driver, Mario Vasquez, who is in critical condition. Local press reports reveal that in 2015, the driver was cited and fined for operating a vehicle without a commercial driver’s license. A passenger, Nakia Coleman, on the bus reported that the driver was trying to pass another vehicle that he apparently expected to yield, but didn’t. “It kind of ran him off the road,” The National Transportation Safety Board has been brought in to help with the investigation.

The bus was operated by Autobuses Coordinados, USA, which operates discount bus service on the West coast. There has been no statement from the company and calls to their Los Angeles were not answered. The bus started its journey in Mexico,and was on its way to the Pasco, Washington when the accident took place.