Monday marks the 67th anniversary of the atomic bombing of Hiroshima, Japan to hasten the end of World War II and hundreds of Bay Area peace protesters marked the event by marching to the gates of the Lawrence Livermore Laboratory.

A crowd of 200 people Sunday marched, then covered the lab's gates with signs, paper chains and makeshift locks for the lab's past and current work with nuclear weapons.

"Part of the reason we're here is to say never forget," said Marylia Kelley, a protester with Communities Against a Radioactive Environment. "The bombings were horrific. People were vaporized."

People gathered a nearby park to remember the 1945 atomic attacks.

Takashi Tanemori survived the Hiroshima bombing and told the crowd it was important to remember the past and use it to shape the future.

"I saw a flash in the sky, a bright flash," Tanemori said to the crowd.

At Sunday's event, many criticized the lab's $975 million budget request  to fund its nuclear weapons activities.

Anne Stark, a Lawrence Livermore Lab spokeswoman, said she understands the emotion linked to the anniversary of the Hiroshima bombing.

"Of course it was a tragedy," she said. "I'm saying that as a citizen, it was a tragedy."

The programs at the lab are not designed for destruction, but for national security, Stark said.

"We don't design any new weapons," Stark said. "There are no new weapons, but what we do is make sure the old weapons from 1945 are still safe and secure."

Security at the lab was tightened ahead of Hiroshima Day, which was also commemorated in nearly 40 cities across the country.