A tourist helicopter crashed in the Grand Canyon in the United States’ Arizona on Saturday, killing three people and injuring four, AP reported.

Six passengers and a pilot were on board the Papillion Grand Canyon Helicopters chopper when it crashed at the Hualapai Nation near Quartermaster Canyon, Hualapai Nation Police Chief Francis Bradley was quoted as saying. The four people who were injured were treated at the spot, Bradley added.

Federal Aviation Administration spokesperson Allen Kenitzer said the reason for the crash was yet to be ascertained, and the chopper suffered heavy damage. Federal authorities are expected to investigate the incident.

The Grand Canyon is one of the most visited tourist attractions in the United States.