A helicopter flying tourists to see the Hoover Dam crashed on Wednesday near Lake Mead, east of Las Vegas, Nevada, killing four passengers and a pilot, local television reported.
All aboard the craft died, the television reported citing the National Park Service.
The chopper was on a tour of Hoover Dam and heading back, Fox television in Las Vegas reported, quoting Sundance Helicopters.
The cause of the crash was not immediately known. The Federal Aviation Administration and National Transportation Safety Board were investigating.