On Tuesday, the U.S. Department of Transportation's Federal Motor Carrier Safety Administration (FMCSA) issued an unsatisfactory safety rating and placed out-of-service N.C.-based bus company Sky Express Inc. for violating multiple federal safety regulations. Under the out-of-service order, Sky Express is prohibited from operating in interstate transportation services.

"Safety is our number one priority," said U.S. Transportation Secretary Ray LaHood. "We will use every resource at our disposal to pursue and remove from our roads unsafe, reckless bus companies."

FMCSA issued the unsatisfactory safety rating and out-of-service order following a full compliance review of Sky Express, which found multiple violations in the areas of driver qualification requirements, drug and alcohol compliance, hours-of-service and vehicle maintenance.

"FMCSA will not tolerate passenger bus companies that endanger public safety," said FMCSA Administrator Anne S. Ferro. "Working side-by-side with our North Carolina state law enforcement partners, we took strong action to shut down this unsafe bus company."

Sky Express was involved in a fatal crash on I-95 near Fredericksburg, Va. Tuesday that killed four people. FMCSA is working closely with the Virginia State Police to investigate the causes of the crash.