Virginia -- The federal Transportation Department shut down a North Carolina bus company Tuesday hours after one of its buses flipped over on a Virginia highway killing four passengers, but months after the company had amassed one of the worst safety records in the U.S.
In the past two years, Sky Express of Charlotte repeatedly violated federal rules that require bus companies to keep tired drivers from getting behind the wheel and to make sure their drivers have proper licenses, medical certificates and English-language skills, according to records from the Federal Motor Carrier Safety Administration, which oversees bus and truck safety.
SLIDESHOW: Images from the scene
Sky Express' 99.7 score in driver fitness indicates that its record was worse than 99.7% of the nation's 3,900 bus operators. The company had a score of 86.2 in fatigued driving, and had been caught seven times since October 2009 allowing drivers to work excessive hours.
"Why did they allow a company with a safety record this egregious to continue to be on the road?" asked Peter Pantuso, president of the American Bus Association, a trade group.
After a thorough safety review of Sky Express, the Federal Motor Carrier Safety Administration on April 12 proposed shutting the company down. Sky Express appealed the shutdown proposal on May 11 and promised improvements, said Candice Tolliver, agency spokeswoman. The agency rejected the appeal two days later.
Tolliver said the agency could not shut down Sky Express immediately because it must wait 45 days from when it proposes a shutdown. After 45 days - on May 27 - instead of shutting down Sky Express, the agency decided to probe new safety concerns, she said.
"We took the option of extending the investigation by 10 days (from May 27) to further investigate the carrier," Tolliver said. "We wanted to make sure we had an air-tight case to shut the company down completely."
Transportation Secretary Ray LaHood says he is directing the department to end its practice of extending appeals periods for operators found to be unsafe.
Virginia State Police blamed the crash on driver fatigue, a longstanding concern of federal officials and safety advocates and a cause of several major bus crashes in recent years. The Sky Express bus was carrying 58 passengers from Greensboro, N.C., to New York City's Chinatown when it ran off Interstate 95 near Richmond about dawn Tuesday and flipped over. Fifty-four people were injured.
Driver Kin Yiu Cheung, 37, of Queens, N.Y., was charged with reckless driving. He suffered minor injuries and was being held at a local jail.
The sequence described Tuesday by Virginia police - a tired driver drifting off a highway - caused a 2008 bus crash that killed nine passengers in Utah and a 2004 bus crash that killed 14 passengers and the driver in Arkansas, according to reports by the National Transportation Safety Board. The NTSB is investigating Tuesday's crash, and the company said it would cooperate.
Meanwhile, investigators are looking into whether fatigue caused a March 12 bus crash near New York City that killed 15 passengers. The company operating that bus, World Wide Travel of Brooklyn, N.Y., had five violations of fatigued-driving rules in the 22 months before the crash.
Bus drivers can drive up to 10 straight hours before being required to take eight hours off, and can work 15 hours, which includes non-driving time, before having to take an eight-hour break.
Safety advocates say the time-off requirements aren't enough to ensure drivers are rested. "It's impossible to get seven to eight hours of sleep," said Henry Jasny, an attorney for Advocates for Highway and Auto Safety.