A sports utility vehicle carrying a large, multiracial family from Washington state drove straight off a scenic cliff on the California coast last week, killing at least six people in what appears to have been an intentional wreck, police said.

The wrecked GMC Yukon was discovered March 26, only three days after child welfare authorities in Washington state opened an investigation into allegations the children were being neglected, social and health authorities said.

The SUV appears to have been stopped by the side of the road in Mendocino County, about 180 miles (290 km) north of San Francisco, before accelerating to as fast as 90 mph (145 kph) and hurtling off a cliff, acting Assistant CHP Chief Greg Baarts told a reporters on Sunday.