Navy explosive ordnance disposal technicians Monday detonated explosives to destroy two World War II-era 100-pound gravity bombs and removed other ordnance from the highly traveled channel between Lanikai and Mokulua North, otherwise known as Mokunui Islet.
The explosion, sending a geyser of water high into the air, surprised some in the area. Several watercraft were visible at the spot 400 yards offshore prior to the detonation.
Law enforcement shooed kayakers from the vicinity of the popular route to Mokulua North and had beachgoers leave the water for the detonation.
An individual had reported possible unexploded ordnance in February, the state Department of Land and Natural Resources said.
The Navy’s Explosive Ordnance Disposal team Detachment Mid-Pacific set off C-4 explosives attached to the two 100-pound bombs.
The explosion was likely caused by the C-4 and not necessarily from the old “UXO,” or unexploded ordnance, DLNR said. The munitions may have been dropped during wartime training, but officials aren’t sure how the bombs ended up off Lanikai.
Prior to the detonation of the two 100-pound gravity bombs, blown up because fuses were still visible, the team brought eight smaller potential unexploded bombs to shore that did not have fuses or fins.
The 100-pound bombs were detonated in place because of the possible danger, officials said. The other bombs or pieces of ordnance without fuses were taken in an inflatable boat to Bellows for transport to Pearl Harbor or Schofield Barracks for demolition.
Biologists from the DLNR Division of Aquatic Resources conducted an assessment last month to assess and document coral in the area and will revisit the site this week to determine the impact of the UXO mitigation effort.
All of the offshore islets are state wildlife sanctuaries. A perimeter path around Mokulua North is the only section visitors are allowed to traverse.
Unexploded ordnance from training before and after the Dec. 7, 1941, attack that launched America into World War II is routinely discovered in Oahu’s waters and on land.
Military aircraft also are occasionally discovered. In 1977 three teens were spearfishing in Kailua Bay when they found the wreck of a World War II-era P-40 Warhawk fighter in relatively shallow water.
Ammunition and two .50-caliber and two .30-caliber machine guns were found with what was left of the plane.
DLNR is responsible for managing, administering and exercising control over public lands, water resources, ocean waters, navigable streams and coastal areas.
Unexploded munitions left behind from historical military activities in areas around the state still pose a serious risk if disturbed, DLNR said. No injuries or deaths in Hawaii have been attributed to UXO since extensive public education efforts conducted by the U.S. Army Corps of Engineers and the state Department of Health, the state agency said.
DLNR offered a reminder of the 3 R’s of UXO safety:
>> Recognize — when you may have encountered a munition and the potential danger.
>> Retreat — do not approach, touch, move or disturb it, and carefully leave the area.
>> Report — call 911 or the DOH HEER Office at 586-5815.