The U.S. Navy located the wreckage Wednesday of a fighter jet that crashed in Washington state during a routine training flight in mountainous terrain. The two crew members onboard remain missing.

The EA-18G Growler jet from the Electronic Attack Squadron crashed east of Mount Rainier at about 3:23 p.m. Tuesday, according to Whidbey Island Naval Air Station. Search teams, including a U.S. Navy MH-60S helicopter, launched from NAS Whidbey Island to try to find the crew and examine the crash site.

Aerial search crews located the wreckage at about 12:30 p.m. Wednesday, Mike Welding, spokesperson for the air station, said in a statement. The crash site was on a mountainside east of Mount Rainier, he said. The status of the crew was unknown. The Navy plans to deploy search teams into the remote area that is not accessible by motorized vehicles. Snow is expected in the Cascades through the weekend.

Navy officials said they didn’t know if the two crew members managed to eject before the crash, which remains under investigation.

The EA-18G Growler is similar to the F/A-18F Super Hornet and includes sophisticated electronic warfare devices. Most of the Growler squadrons are based at Whidbey Island. One squadron is based at Marine Corps Air Station Iwakuni, Japan.

The “Zappers” were recently deployed on the USS Dwight D. Eisenhower.

The search Wednesday was happening in rainy and cloudy weather near Mount Rainier, a towering active volcano that is blanketed in snowfields and glaciers year-round.

The first production of the Growler was delivered to Whidbey Island in 2008. In the last 15 years, it has operated around the globe supporting major actions, the Navy said. The plane seats a pilot in front and an electronics operator behind them.

“The EA-18G Growler aircraft we fly represents the most advanced technology in airborne Electronic Attack and stands as the Navy’s first line of defense in hostile environments,” the Navy said on its website. Each aircraft costs about $67 million.

Military aircraft training exercises and travel can be dangerous and sometimes result in crashes, injuries and deaths.

In May, an F-35 fighter jet on its way from Texas to Edwards Air Force Base near Los Angeles crashed after the pilot stopped to refuel in New Mexico. The pilot was the only person on board in that case, and was taken to a hospital with serious injuries.

Last year, eight U.S. Air Force special Operations Command service members were killed when a CV-22B Osprey aircraft they were flying in crashed off the coast of Japan.