Zoƫ Keliher, an air safety investigator with the National Transportation Safety Board, on Monday combs through the wreckage inside a hangar at the St. George Airport of a single-engine plane that crashed early Saturday, killing four people. The plane crashed just after takeoff, at about 1:20 a.m. The wreck was found at about 5:30 a.m. during a routine security check, Keliher said.