The driver of a bus that swerved off an Irving highway, leaving two passengers dead and dozens injured, was at the wheel in another fatal crash 15 years ago, but an official Friday downplayed the importance of the earlier accident to the pending investigation.The Texas Department of Public Safety confirmed that Loyd Rieve, 65, was driving the tour bus Thursday that veered across Texas 161 in Irving and into the center median with 46 passengers aboard.The bus was operated by Cardinal Coach Line Inc. Court records show that Rieve was driving for another company in 1998 when he struck and killed a man who was trying to render aid at an accident scene on a highway near Dallas.DPS spokesman Lonny Haschel said authorities will interview Rieve and review his driving record. But Haschel said the 1998 accident will not have any bearing on the investigation into Thursday's wreck.Rieve remained sedated and in intensive care Friday after suffering three broken ribs, according to his wife, Gail Rieve.She said her husband, a bus driver for 32 years, remembers little about Thursday's crash."He came up on the barricade thing," she said. "The next thing he remembers is being in front of the bus."A Dallas County grand jury declined to indict Rieve on a charge of negligent homicide stemming from the 1998 collision, but Rieve and his employer still faced two civil lawsuits that contended they were negligent.One lawsuit, filed by the family of the man who was killed, alleged that Central West Motor Stages Inc. of Grand Prairie hired and retained Rieve when it knew or should have known he was unfit and incompetent.It resulted in a jury finding that the company was negligent for employing Rieve. However, the jury awarded no damages, deciding that the good Samaritan, 22-year-old Chad Rosell of Detroit Lakes, Minn., was largely at fault.