The aircraft was taking off with three others on their last flight out of Guam after a four-month deployment, part of a continuous U.S. bomber presence in the western Pacific. After the crash, the other three bombers were being kept on Guam, said Maj. Eric Hilliard at Hickham Air Force Base in Hawaii.
At least one B-2 bomber had taken off safely from Andersen Air Force Base but was brought back when another aircraft plunged to the ground.
There were no injuries on the ground or damage to buildings, and no munitions were on board. Each B-2 bomber costs about $1.2 billion to build.
Thick, black smoke could be seen billowing from the wreckage at Andersen, said Jeanne Ward, a resident in the northern village of Yigo who was on the base visiting her husband.
Ward said she didn't witness the crash but noticed a rising plume of smoke behind the base's air control tower.
She said crowds began to gather as emergency vehicles arrived. "Everybody was on their cell phones, and the first thing everyone wanted to know was did the pilots make it out in time," she said.
The Air Force, without identifying the pilots, said one was medically evaluated and released, and the other was in stable condition at Guam Naval Hospital.
A board of officers will investigate what caused the bat-like aircraft to crash at 10:30 a.m., shortly after taking off from a runway. It was the first crash of a B-2 bomber, said Capt. Sheila Johnston, a spokeswoman for Air Combat Command at Langley Air Force Base in Virginia.