Five killed as Alaska sightseeing plane

Small plane crashes on sightseeing tour in mountainous area of Alaska

Four cruise ship passengers and plane's pilot killed

(CNN) -- Rescue authorities reported all five people aboard a small sightseeing plane were killed when it crashed in a mountainous area of southeast Alaska on Tuesday, a Princess Cruises spokeswoman said.

The five included the plane's pilot and four Sun Princess cruise ship passengers, who were on the second day of a weeklong, round-trip cruise from Seattle, Washington, spokeswoman Julie Benson said in a statement.

The pilot sent out a distress signal late Tuesday afternoon while on a planned tour of Misty Fjords National Monument, south of Juneau near Ketchikan, Alaska, according to Benson.

When the single-engine DeHavilland Beaver did not return, "rescue helicopters were dispatched to the location of the flight seeing route," Benson said. "These helicopters subsequently spotted the float plane which ... crashed in rugged terrain."