An investigation was under way Saturday into the crash of a small plane in Spain that killed three of the four people aboard, authorities said. The pilot of the single-engine plane was seriously injured and taken to a hospital in Palma. A firefighter and a bystander suffered minor burns while trying to get the victims out of the flaming wreckage, UPI reported. The crash occurred in a brushy area near Marratxi, on the island of Majorca. The cause of the crash was not immediately known.