A deadly helicopter crash near the Grand Canyon on Friday night has led a Las Vegas-based sightseeing company to ground all of its flights.
The company has been involved in several major crashes.
The helicopter was returning to Las Vegas when it slammed into the Grand Wash cliffs, 70 miles east, where the red rocks are a popular sightseeing location for tourists.
The pilot and what is believed to be five members of one family died. Authorities say a second helicopter carrying other family or friends passed over the scene and reported the accident.
Witnesses said the wreckage was still burning hours later when rescuers reached the one survivor.
"While we really don't know what happened here, the probability of a mechanical accident is rather high," said ABC's aviation analyst John Nance.
Eleven People Killed Since 1985
Papillon Helicopters, which also operates in Hawaii, is a popular sightseeing company that safely transports thousands of tourists every year. But the company has had 15 accidents since 1985, four of them fatal, killing a total of 11 people.
Just last September, one of Papillon's choppers crashed near Boulder Dam outside Las Vegas.
"Given the numbers of hours this company flies helicopters, it's very difficult to say whether this record is completely off the charts, but certainly it's alarming," Nance said.
An estimated 800,000 people a year fly over the Grand Canyon in helicopters and fixed-wing aircraft, but the industry has been plagued by accidents that have killed nearly 50 people in the last 15 years.
The collision between an airplane and a helicopter in 1986 led to regulations that tourist flights may not drop below the level of the Grand Canyon rim in order to avoid crowding in the confinement of the canyon. But safety experts say tourists still need to be aware of the potential danger.
"They're going to be flying in an area where there's other aircraft, and that their level of risk between that flight and flying into a city where your vacation is on a commercial airline … the risk of a tour is going to be greater," said Michael Barr from the University of Southern California Aviation Safety Program.
Investigators from the National Transportation Safety Board are expected to visit the remote crash site Sunday.
ABCNEWS' Brian Rooney in Los Angeles contributed to this report.