(NewsNation) — A tourism helicopter carrying six people crashed Wednesday in a Hawaii lava field.

The incident happened at 5:29 p.m. while the aircraft, a Bell 407 from K&S Helicopters, was operating a tour, NewsNation local affiliate KHON2 reported.

The 50-year-old male pilot and an 18-year-old female passenger were in serious condition following the crash, Cyrus Johnasen, a public information office for Hawaii County, said. The four other people were reported as ambulatory.

The site was inaccessible by vehicle so the Hawaii Fire Department sent two helicopters to take victims to ambulances waiting on nearby roads.

No information was immediately released on what caused the crash.

K&S Helicopters said they initiated an emergency response plan and the full resources of the company are being mobilized to respond to the incident.

“The care of our passengers, crew members and their families is our highest priority,” said Calvin Dorn of K&S Helicopters.