Authorities on Saturday identified three of the seven victims of a deadly tour helicopter crash in Hawaii.

All on board were killed when the craft went down Thursday in a remote area of the Na Pali coast on the island of Kauai. The cause of the crash remained under investigation.

Among the dead were the pilot, Paul Matero, 69, of Wailua, and Amy Gannon, 47, and Jocelyn Gannon, 13, both of Wisconsin. Kauai police said in a Facebook post that autopsies were being conducted to confirm the identities of the others. Police said they are believed to be a family from Switzerland.

"There are no indications of survivors," Kauai Fire Battalion Chief Solomon Kanoho said Friday after the remains of six victims were found near the crash site in a remote area of the rugged north coast.

The Coast Guard cutter William Hart moves toward the Na Pali Coast on the Hawaiian island of Kauai on Friday, the day after a tour helicopter disappeared with seven people aboard. Lt. j.g. Daniel Winter / U.S. Coast Guard via AP

The helicopter had been reported overdue around 6 p.m. Thursday, setting off a search that ended with the grim discovery of wreckage and, later, bodies.

"We mourn with the family members of those who were lost in the tragic accident," the tour operator, Safari Helicopter, said in a statement, which said the company was "fully cooperating" with investigators.

The company said its pilot, Matero, was a "seasoned member" with 12 years of experience touring Kauai.

Kanoho said Friday that there were members of two families on board, a party of two and a party of four.

The National Transportation Safety Board said it was sending three investigators to the scene.

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It was the third helicopter crash in Hawaii this year, according to NBC affiliate KHNL of Honolulu.

Rep. Ed Case, a Democrat who represents a congressional district in Hawaii that includes Honolulu, said in a statement Friday that more must be done to regulate the tour and small-aircraft industries and to improve safety.

In September, Case introduced a bill that he said would strictly regulate commercial tour operators, including helicopters and small planes. It would require that tour flight pilots focus on flying the aircraft and not act as tour guides. It also would restrict where they could fly and how low.

The Federal Aviation Administration said it conducts random and regular surveillance on all Hawaii air tour operators and ensures that companies address any issues. Ian Gregor, a spokesman for the FAA, told The Associated Press that the agency does not have concerns about the industry statewide.