Two Army grounds maintenance contractors suffered "severe" injuries Monday from an explosive that detonated at Makua Military Reservation, officials said.
A Honolulu Fire Department spokesman said the explosive was set off by a hand-held grass trimmer.
Another worker nearby also was injured in the explosion, said department spokesman Capt. David Jenkins.
The incident was reported at 1:45 p.m., and a contracted medevac helicopter used by the Army transported the workers to the Queen’s Medical Center, officials said.
It is unclear exactly what exploded, but it could have been a mortar round, antitank round or a heavier air-dropped bomb, given the history of live-fire training in the valley.
"I did find out from our personnel there that arrived on scene, they were civilian contractors," Jenkins said. "One was operating a grass trimmer when he made contact with the unexploded ordnance. Of course, the person closer had more injury, and the (other person) was a little bit farther away and his injuries were less. I can’t really go into the actual details, but they were both severe."
The contractors work for NuGate Group LLC, the Army said. Company representatives could not be reached for comment Monday afternoon.
"It appears some type of (unexploded ordnance) did detonate; however, the details and circumstances surrounding the incident are still under investigation," U.S. Army Garrison Hawaii said in an email.
"The injured individuals are in our thoughts and prayers," said Stefanie Gardin, an Army spokeswoman.
David Henkin, an Earthjustice attorney who has waged a legal battle for more than 15 years against the environmental effects of Army munitions training in Makua on behalf of community group Malama Makua, said despite past cleanups, unexploded ordnance, or UXO, remains.
"For about 1,000 meters from the fence line heading inland, the Army already completed a lot of sweeps and removed a lot of ordnance — I mean, everything up to 1,000-pound bombs," Henkin said. "And then within the reservation they are supposed to have cleared unexploded ordnance from all the areas where they cut grass as well as the accesses to the cultural sites."
Malama Makua sued the Army in 1998 to secure a comprehensive review of the effects of 75 years of live-fire military training in the 4,190-acre Waianae Coast valley, which is home to more than 50 endangered plant and animal species and more than 100 archaeological features.
The Army agreed under a 2001 court settlement to conduct an environmental impact statement. No live-fire training has been conducted in the valley since June 2004 because the courts have ruled that the Army still hasn’t completed the study.
Blank-fire, convoy, maneuver and unmanned aerial vehicle training have since been conducted in the valley.
"Since the 2001 agreement, I’m not aware of any (other) accidents involving unexploded ordnance," Henkin said.
Henkin previously said the Army removed a 100-pound bomb from the valley in 2011. In late 2007 an old World War II 250-pound bomb discovered beneath an interior access road was detonated, along with an 81 mm mortar and 106 mm antitank round that had been found.
"My understanding is that there are a variety of ways in which ordnance can show up in places that have been cleared," Henkin said.
One way is by rain washing down munitions to a lower area through erosion.
"Also, occasionally things percolate up like rocks in a farmer’s field," Henkin said.
"Definitely, safety I think is a concern of the Army’s. It’s definitely been a concern of Earthjustice and Malama Makua, which is why we follow all (the Army’s) protocols for cultural access, and it’s definitely very unfortunate if a grass cutter maintenance person has been hurt," Henkin said.
He said his understanding is no grass cutting is being done for cultural access, meaning the work being done was training-related.
"And those areas are very frequently used by soldiers, so this is definitely very unfortunate and regrettable but very unusual," he said.
According to a 2013 Army report, there has been a long history of military use of the entire Kaena Point area. In the 1920s the U.S. military used three parcels on the upper Makua Valley floor for howitzer emplacements.
From Dec. 7, 1941, until 1946, the entire Makua-Kaena Point area was occupied under martial law for training and security operations. Invasion training in Makua included Navy aerial bombing and battleships shelling the bowl-shaped valley from the sea.
