A helicopter carrying four passengers on a luxury sunset tour collided into a mountainside Wednesday night, killing all five people on board, including the pilot. Due to the remoteness of the crash, recovery of the bodies and investigation into what caused the crash will be complicated, investigators said.

The helicopter, operated by Sundance Helicopters, crashed into the River Mountains shortly before 5 p.m., said National Park Service spokesman Andrew Munoz, according to The Associated Press. The crash occurred during a sunset sightseeing flight over the Las Vegas Strip and Hoover Dam.

Authorities have yet to release the names of the passengers, but Sundance Helicopters said the pilot was Landon Nield, 31. He had just gotten married in June, the AP reported.

U.S. Sen. Harry Reid issued a statement mourning the deaths.

“Hundreds of thousands of tourists enjoy these popular helicopter tours of Nevada each year,” Reid said, “and I’m saddened that people lost their lives in this rare tragedy.”

Sundance Helicopters had another fatal accident in Sept. 2003, when a helicopter slammed into a canyon wall near the Grand Canyon. All six passengers and the pilot were killed.

Follow us

The pilot in that crash had allegedly received at least two written complaints from passengers for reckless flying. However, no disciplinary action was taken, the AP reported.

“All our helicopters are maintained with exacting precision and our pilots are trained then retrained with ongoing re-certification in excess of FAA requirements,” says Sundance Helicopter's website.

On Nov. 10, a tour helicopter on a flight over West Maui also slammed into a mountainside, killing all five people on board after bursting into flames.

A National Transportation Safety Board report on that crash said the pilot failed to “maintain enough altitude over the terrain amid low-lying clouds,” causing the helicopter to slam into the side of a ridge, Fox News reported.

Two of the passengers were newlyweds on their honeymoon.

Tour helicopters have come under tighter scrutiny as more crashes have been reported in recent years. After a tour helicopter crash in New York City in October, local politicians called for a complete ban on the leisure vehicles in the city.