At least three people were killed when their plane crashed into a home in Gaithersburg, Maryland, and several residents of the home are unaccounted for, Montgomery County Fire Department spokesman Pete Piringer said. The small jet crashed around 10:45 a.m. Monday in the 19000 block of Drop Forge Lane, near Snouffer School Road.Piringer did not know whether the pilot was among the dead. No one was found inside the home during an initial search. The Montgomery County Airpark is about one mile from the scene, which is scattered with debris. Two other homes also were badly damaged.