Authorities say a tour bus that crashed closed to the Arizona-Nevada border after the driver had a heart attack was packed with Australian tourists.
Arizona Department of Public Safety also identified the driver, who died at the scene, as 52-year-old Ronnie Sparks of Nevada.
Investigators say after Sparks suffered a heart attack his vehicle hit a ravine, tore up a small hill, then bounced and lurched over rough terrain for more than 700 feet before stopping.
DPS spokesman Bart Graves says 48 Australian tourists were on the bus. He says six sustained serious head and other injuries and were at the University Medical Center of Southern Nevada.
Tony Fiorini, president of Silver State Trailways, the charter-bus company, says passengers were transported by the company back to their Las Vegas hotels.