TWIN FALLS, Idaho -

Authorities are investigating a 28-year-old California woman's death as a suicide after her van accelerated off the roadway and fell 300 feet into the Snake River Canyon.

Jerome County authorities say the crash happened after Monica Louise Fisher of Indio, Calif., left her parents in Hailey on Sunday.

Sheriff Doug McFall tells the Times-News that the van left the roadway on the Snake River Canyon's north rim about a quarter-mile east of the Perrine Bridge.

McFall says Idaho State Police investigators found evidence that Fisher accelerated just before reaching the rim.

The van plunged 300 feet, coming to a rest about 350 feet above the water.

Besides Fisher, rescue personnel spent hours searching the canyon for any passengers, but nobody was found.