Rescue personnel who were aiding an injured woman on the rocky coast near Crescent City on Friday night had to be rescued themselves by the Sonoma County sheriff's helicopter after they became trapped by rising waves.

The emergency began when a 27-year-old woman fell about 20 feet onto some rocks below a cliff topping 100 feet, Sonoma County Sheriff's Deputy Chris Mahoney said. She had suffered head injuries, broken bones and cuts, he said, and her male companion also was hurt, though not as badly.

Park rangers, Del Norte County Sheriff's deputies, firefighters, emergency medics and civilian search and rescue volunteers were among nine people who responded around 6:45 p.m., Mahoney said.

They prepared the pair to be transported by a U.S. Coast Guard helicopter, Mahoney said. The woman was flown to UC Davis Medical Center in Sacramento, he said.

Meanwhile, the tide had come in, trapping the nine rescuers on the rocks, Mahoney said. Del Norte County officials contacted the state Emergency Services Office, which arranged for help from Henry 1, the Sonoma County sheriff's helicopter.

Although Henry 1 frequently assists out-of-county agencies, this flight was unusually long — 3? hours, including fuel stops, Mahoney said.

The trapped rescuers were on the rocks for about five hours, getting sprayed by the ocean and battered by winds. Several were in the early stages of hypothermia as the Henry 1 crew arrived with its 100-foot long line and ferried them, two at a time, to the top of the cliff, Mahoney said.