Authorities say the number of drunk driving arrests and the number of highway fatalities more than tripled in Iowa over the Christmas holiday. Sergeant Rob Hansen, spokesman for the Iowa Highway Patrol, says seven people were killed in five wrecks that were investigated by troopers, including two fatal accidents that killed four people within ten minutes of each other in western Iowa on Sunday morning. Sergeant Hansen says the winter weather that struck over the holiday was partly to blame. He adds that last year, there were only two during the holiday weekend. Hansen says the troopers were also rather surprised that the number of drunk drivers picked up this year was 23, compared with seven DWI arrests during the holiday of 2001.