A commercial bus traveling from North Carolina to New York ran off Interstate 95 and flipped over on its roof on Tuesday morning. Driver fatigue is being cited as the likely cause. The accident killed four people and injured more than 50; the bus had 57 passengers aboard. The accident occurred in Caroline County; the bus ran off the interstate, hit an embankment, and then flipped over. The bus was owned by Sky Express Inc., which has a bad inspection history. The company performed worse than 97 percent of all passenger-bus companies within the past 12 months and 86.2 percent worse in the past 24 months in the “fatigued driver” category.