Rescue crews were searching for a surfer missing on Oahu's North Shore Wednesday.
The U.S. Coast Guard and police identified the missing man as 32-year-old Kirk Passmore of Haleiwa.
According to Emergency Medical Services officials, witnesses saw a surfer in distress near Alligator Rock in Haleiwa at around 11:20 a.m.
A witness said Passmore wiped out on what was described as a 20-foot-tall wave. Passmore was seen kicking with his feet out of the water, and he was lost in the white water.
Passmore's partially damaged surfboard was located further down the beach.
The missing surfer is described as an experienced surfer.
A fire department helicopter, a Coast Guard helicopter and two lifeguards on watercraft are searching for the surfer.
Lifeguards and fire crews were set to search until sunset and resume on Thursday. The Coast Guard will search through the night.
Alligator Rock is between Waimea Bay and Chun's Reef. It's the same place where big-wave rider Todd Chesser died back in 1997.
A high surf warning is in effect for the north and east shores of Kauai, Oahu, Molokai, Maui and the Big Island until Thursday morning.