Authorities say a tour helicopter has crashed in the Grand Canyon, killing three people.

Hualapai Nation Police Chief Francis Bradley said six passengers and a pilot were on board the Papillon helicopter when it crashed about 5:20 p.m. The other four were injured and were still being treated at the scene.

An after-hours phone call to aerial tour company Papillon was not immediately returned Saturday. The company’s website says it flies roughly 600,000 passengers a year on Grand Canyon and other tours.

Federal Aviation Administration spokesman Allen Kenitzer said the Eurocopter EC130 crashed in unknown circumstances and sustained heavy damage.