A helicopter crash has killed a pilot and four passengers on a tour of the Las Vegas Strip and Hoover Dam.

National Park Service spokesman Andrew Munoz said Wednesday that the aircraft operated by Sundance Helicopters crashed into the River Mountains surrounding Lake Mead just before 5 p.m.

A security guard from the national recreation area heard the crash and reported seeing smoke about 4 miles west of the lake's edge.

Munoz says everyone on board was killed.

The crash site about 30 miles from the Las Vegas Strip is not accessible by road.

A September 2003 crash of a Sundance Helicopters flight killed its pilot and six passengers in Arizona. Unsafe flying procedures and misjudgment were cited as the probable cause of that crash.

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