A third vehicle also was involved in the accident. Two occupants of that vehicle survived.

The wreck occurred on Highway 11 at the 28-mile marker, near the park boundary.

A car driven by a man with two female passengers was traveling in the Ka'u direction when it collided with two cars heading in the Hilo direction, the release said.

All three people in the Ka'u-bound vehicle were killed.

A man and woman in the first Hilo-bound car were killed as well.

A man driving the second Hilo-bound car was taken by ambulance to Hilo Medical Center, from where he was flown to The Queen's Medical Center in Honolulu.

A male passenger in that same car refused medical treatment and was released at the scene, according to the release.

According to information from the Hawai'i County Fire Department, which responded to an 11:07 p.m. alarm, all three vehicles involved were extensively damaged, requiring firefighters to extricate bodies and victims from the wreckage.

Because the incident happened on park property, the ongoing investigation is being headed by federal officials.