A US military UH-60 Black Hawk helicopter went missing while training with another helicopter near Hawaii on Tueday night.
The aircraft disappeared at approximately 9:30p.m. on Tuesday, approximately two miles from the westernmost tip of Oahu, the US Army reported.
Meanwhile, the second helicopter immediately reported the loss of visual and radio contact to headquarters. Search efforts began almost immediately.
Approximately two hours later, the US Coast Guard reported a debris field in the area.
Authorities - including the Coast Guard, Marines, and local fire department - are now searching for the missing crew members.
"This is still a search and rescue mission. We are here to bring our soldiers home," a military spokesman said. "I'd like to express that our thoughts and prayers are with the families of the soldiers in this difficult time."
Earlier in August, an Israeli Apache helicopter crashed, killing one if its two crew members and severely injuring the other.