Norris Bradbury; Head of Los Alamos

Norris Bradbury, the physicist who helped assemble the first atomic bomb and then headed the key Los Alamos nuclear laboratory for 25 years of the Cold War, has died at age 88.

His family and officials at the Los Alamos National Laboratory said Thursday that Bradbury died at his home Wednesday night.

Bradbury joined Los Alamos’ top-secret Manhattan Project in 1944 and led the team charged with assembling the non-nuclear components for the world’s first atomic bomb explosion.

That explosion, July 16, 1945, at the Trinity site in southern New Mexico, set up the bombing of the Japanese cities of Hiroshima and Nagasaki the next month.

With the end of World War II, Bradbury was asked to take over as director of Los Alamos from laboratory founder Robert Oppenheimer. He reluctantly agreed to step into the job for six months, but ended up staying for 25 years, leading the top secret facility as it developed nuclear and conventional weapons during the first decades of the Cold War.

Bradbury’s supporters say his leadership was largely responsible for Los Alamos developing the first thermonuclear weapons and other weapons.

But he had his critics.

“It is not to his credit that the above-ground nuclear test program, which was a public health debacle of the first magnitude, was developed at that time,” said Greg Mello of the Los Alamos Study Group in Santa Fe. “Norris knew it was dangerous and, to my knowledge, did nothing to stop it.”

But even Mello said Bradbury was an honest, straightforward man who truly believed in building an effective deterrent, and praised him for saying in the late 1970s that the United States’ nuclear stockpile could be maintained without new testing.

Bradbury is survived by his wife, Lois, and three sons.