The bus operator involved in a deadly Utah crash that killed three members of a Japanese tour group and injured 11 other passengers is under investigation for operating across state lines without a license, a federal official said Thursday.

Canyon Transportation Inc., of the Salt Lake suburb of Sandy, faces fines that could be significant if the company didn't have enough liability insurance for interstate operators, said Bob Kelleher, administrator for the Utah office of the Federal Motor Carrier Safety Administration. He couldn't immediately provide any figures.

"We're conducting a full investigation, following up to determine whether the company met all the regulations," Kelleher said.

Canyon Transportation apparently fell between the regulatory cracks. Kelleher said the Utah Department of Transportation was supposed to regulate the company, but the state agency couldn't cite any inspections or enforcement activity.

"Up until a couple of days ago, I didn't know anything about this company," Kelleher told The Associated Press. The company mostly picks up people from Salt Lake City's airport for short rides to ski areas and wasn't supposed to operate outside of Utah, he said.

Canyon Transportation provided the 2006 Ford E350 shuttle bus that picked up a group of 14 Japanese tourists in Las Vegas for a four-day tour of Utah's national parks and Arizona's Grand Canyon, according to the Utah Highway Patrol and tour organizers. The group set out Monday and the bus rolled that evening on Interstate 15 near Cedar City, about 250 miles south of Salt Lake City.

Hiroki Hayase, a 20-year-old man from Osaka, was killed in the crash, and authorities Thursday identified the two others who died as Junji Hoshino, 38, and his wife Junko Hoshino, 40, from Shinjuku.

A database managed by the Federal Motor Carrier Safety Administration shows that Utah recently issued logbook violations against Canyon Transportation's drivers. The federal database indicated no other state enforcement activity or violations against the company.

Kelleher said the lack of any other activity in the federal database means the Utah Department of Transportation wasn't regularly inspecting the small operator or enforcing any rules.

State transportation officials said they had no enforcement records on Canyon Transportation and that it wasn't clear if their inspectors issued the logbook violation. It could have been entered by Utah troopers or port of entry officials.

"If we do have any records, we would have already given them to the feds," said UDOT spokesman Adan Carrillo, who acknowledged his agency was responsible for regulating the company.

A Canyon Transportation dispatcher said no executives were available for comment, but another company involved in the tour says the bus operator has been operating across state lines for years without a fatal accident.

"My understanding is they've done plenty of interstate work. They've been in business for 30 years," said Keith Griffall, CEO and co-owner of tour organizer Western Leisure Inc.

Griffall said he has worked with Canyon Transportation for years but Thursday was the first time he heard it lacked a federal license to operate across state lines.

"As far as the regulations go, they get so technical — I don't know anything about that," he said.

Kelleher said other bus operators obtain interstate licenses and there was no question that Canyon Transportation lacked authority to run buses outside of Utah.

The driver, Yasushi Mikuni, 26, is under investigation by Utah troopers who say he was distracted or drowsy when he rolled the bus. Troopers said they found no mechanical problem that would have caused the crash.

Mikuni, a Japanese national living in Las Vegas on a work and education visa, escaped the accident with minor injuries.

It wasn't clear if the driver, a part-time student at the College of Southern Nevada, had a commercial driver's license. Kelleher said a commercial license isn't necessary for a bus with fewer than 16 seats.

Mikuni was ticketed June 1 for speeding on a Utah highway in a Nissan sedan, according to court records. He paid a $115 fine for driving 86 mph in a 75 mph zone in Millard County, records show.

Utah Highway Patrol records show Mikuni also was ticketed May 20 for a tinted-window violation in Juab County, The Salt Lake Tribune reported.

The Ford E350 shuttle bus that rolled over had seat belts, Trooper Todd Johnson said, but it wasn't clear how many of the passengers were wearing them. Kristi Christensen, 31, a nurse who arrived at the wreckage five minutes after the accident, said she found all but three of the 14 passengers thrown from the bus.

Griffall said his company and Nippon Travel Agency in Tokyo were among several companies that helped organize or provided customers for the tour. Those companies hired Canyon Transportation to provide the shuttle bus and its driver, and Griffall said his company was paying the driver separately to double as a tour guide.

Many of the tour companies are helping to pay for lodging and food for accident victims and family members, he said.

"Our thoughts and prayers are with the victims of this tragic accident and their families," Griffall said. "We've been in business for 30 years and never had a fatal accident. We're a small company, and everybody here is feeling the grief and sorrow."