Ketchikan, AK (Ben Caxton) — Three people were killed after two sightseeing airplanes carrying cruise ship tourists collided in mid-air Monday near a southeast Alaska town, the Coast Guard said. Three others are missing after the collision about 10 miles from Ketchikan. The National Transportation Board was sending an elite investigative team from Washington, D.C., to investigate the crash, another deadly mishap for cruise ship passengers taking side excursions off cruise ships in Ketchikan. The floatplanes with passengers from Princess Cruises’ Royal Princess ship collided under unknown circumstances, Federal Aviation Administration spokesman Allen Kenitzer said in an email to The Associated Press. Floatplanes have pontoons mounted under the fuselage so they can land on water. Eleven people were inside Taquan Air’s single-engine de Havilland Otter DHC-3 when it went down as it returned from Misty Fjords National Monument, which is part of the Tongass National Forest, the nation’s largest. Ten were taken to a Ketchikan hospital. All patients were in fair or good condition, according to Marty West, a spokeswoman for PeaceHealth Ketchikan Medical Center.