A Blue Hawaiian tour helicopter experienced engine failure about a quarter-mile off Kauai’s north shore Sunday and was forced to make a “hard landing” on the beach, according to a preliminary report issued by the National Transportation Safety Board.

The preliminary NTSB report said the pilot of Airbus EC130 was at about 1,300 feet when he heard the helicopter’s low rotor warning horn.

He then initiated corrective procedures and turned toward Kalalau Beach, located 2 miles west of Hanalei, the report said. The helicopter was carrying six passengers.

The pilot reported over the radio that he had an engine failure, according to the report. As the plane approached the shoreline, the pilot made a right turn south and landed hard on the beach, the report said.

The EC130 light single-engine helicopter sustained substantial damage to the tail boom and airframe, the report said.

The pilot and two passengers sustained minor injuries. Four other passengers were seriously injured.

On Tuesday, Wilcox Hospital spokeswoman Faith Campbell said paramedics took three passengers from the scene to the hospital, and that they were later transferred to the Queen’s Medical Center on Oahu in guarded condition.

She said the pilot and three other passengers were all in stable condition or discharged from Wilcox Hospital.