Washington, November 25 (RHC)-- A U.S. Army helicopter crash at Fort Hood military base in Texas has left four crew members on board dead, officials say. The UH-60 Black Hawk helicopter which was reportedly on a training mission crashed at 5:49 p.m. local time on Monday at Fort Hood military base, 200 miles northwest of Houston, Texas.

According to a press release by Fort Hood Public Affairs Office: "After an extensive search, emergency crews located the scene of the incident and are reporting the four crew members found dead."

As the Army base said: "They were on a routine training mission at the time," adding that "the cause of the crash is unknown at this time."

Earlier on Monday, a U.S. Army's AH-64 helicopter crashed in the South Korean city of Wonjo, approximately 80 miles east of Seoul, making the bad day for U.S. Army aviation even worse.

The Apache helicopter was carrying two U.S. service members, when, according to South Korea's Yonhap news agency, the helicopter struck a high-voltage electrical tower before tumbling onto a roadway below.

In both cases, the investigation as to the cause of the crash is still underway.