Eight people have been killed after a US Air Force B-52 Stratofortress bomber plane crashed immediately after take off from Edwards Air Force Base in southern California, base officials say.
The incident occurred at 11:20 local time (19:20 GMT) on Monday while the aircraft was on a routine test mission. The crash sent a huge plume of black smoke into the air that could be seen for miles.
"Today, Edwards Air Force Base experienced a terrible tragedy, and we lost eight great Americans," Col James Hayes told reporters, describing them as a "mixed crew of military, government civilians and government contractors".
The base earlier said that initial indications are that the crash "was not survivable".
The crew's next of kin are being notified and they will be named 24 hours after that, Hayes said in an afternoon briefing.
The crash was "totally contained" within the Edwards Air Force Base on the runway, Hayes said, and the base has temporarily grounded operations.
The B-52 was supporting the base's radar modernisation programme, he said, and it crashed immediately after takeoff and burst into flames.
After reviewing initial footage, it was deemed "an unrecoverable crash and unsurvivable", Hayes said.
No cause has yet been determined and will not be until after a series of investigations, which can take up to 30 days. Further cause analysis investigations can take more than six months, Hayes said.
The Boeing B-52 Stratofortress has been used by the US military since the 1950s. It is nicknamed "the Buff", which is partly short for "Big Ugly Fat".
Aerial footage showed a charred, smoking landscape where the crash occurred.
In an earlier update on X, the base said that "the airfield has been closed, and all inbound aircraft are being diverted".
"All non-commercial visitor passes have been suspended until further notice to allow the installation to focus entirely on emergency response operations."
The B-52 is a long-range strategic bomber that has been participating in bombing raids on Iran during the latest US-Israeli war on the country.
Capable of flying at up to 50,000 feet (commercial airliners fly around 35,000 feet) the colossal bomber's 70,000lb payload can include hundreds of conventional bombs and 32 nuclear cruise missiles.
It can refuel in mid-air - giving it a potentially unlimited strike range. This created a "nuclear umbrella" for the United States during the Cold War, back in the era of Mutually Assured Destruction.
They typically carry a crew of five - an aircraft commander, pilot, radar navigator, navigator and electronic warfare officer.
Edwards Base is located around 100 miles (160km) north of Los Angeles, in the Mojave Desert.
Congressman Jay Obernolte, whose district includes the base, posted on Facebook that he and his wife "are praying for everyone involved in today's B-52 crash at Edwards Air Force Base, especially the crew, their families, and the first responders on scene".
Michigan Republican Congresswoman Lisa McClain was also among the lawmakers posting about the crash, writing on X: "My prayers are with everyone involved in the B-52 crash at Edwards Air Force Base this afternoon."
She thanked emergency crews, who she wrote are "responding right now", and added: "Our service members carry the weight of this nation's defense every single day. We are with them."
Source: BBC
--Agencies
