A multi-agency team scoured the ocean off Hawaii on Wednesday for five people aboard an Army helicopter that went down during a nighttime training exercise.

Officials at Wheeler Army Airfield near Honolulu reported losing communications around 10 p.m. Tuesday with the crew of a UH-60 Black Hawk, the Coast Guard said in a statement.

Honolulu Fire Department search and rescue crews found and collected pieces of helicopter fuselage and a helmet in a debris field about 2 miles (3 kilometers) off Kaena Point on Oahu.

Photos showed Army soldiers unloading suspected debris from the firefighters’ boat at the harbor in the nearby town of Haleiwa.

Officials closed the state park at Kaena Point while the search was underway. Kaena is a remote spot where Oahu’s northern and western coasts meet to form a small peninsula. The park’s sandy coastline is home to a seabird colony and endangered Hawaiian monk seals.

A Coast Guard plane, two helicopters and several boats were being used in the search across an area with light winds and 2-foot (0.6-meter) seas.

Two Black Hawk crews were conducting training between Kaena Point and Oahu’s Dillingham Airfield northwest of Honolulu when communications were lost, officials said. Clouds and a few showers were in the area at the time.

Night training offshore is routine, said Lt. Col. Curtis Kellogg, public affairs officer for the Army’s 25th Infantry Division.

The search began immediately after one aircrew lost visual and video contact with the other helicopter, Kellogg said.

The two helicopters are elements of the 25th Combat Aviation Brigade.

The UH-60 Black Hawk is a four-bladed, twin-engine utility helicopter manufactured for the Army by Sikorsky Aircraft starting in the 1970s.

More than 3,000 Black Hawk aircraft are in service around the world, according to Sikorsky’s parent company Lockheed Martin. The U.S. Army owns 2,300 of them.

In April, one crew member was killed and two others were injured when an Army Black Hawk helicopter crashed onto a golf course in Maryland during a routine training flight.

In 2015, 11 crew members were killed when an Army Black Hawk helicopter crashed into the water off Eglin Air Force Base, Florida.

(AP)