Construction worker crushed to death at Moscone Center

A construction worker operating a large cherry picker was crushed to death when he came in contact with a concrete slab in an industrial accident at Moscone Center in San Francisco early Friday, police said.

The man, who was not identified, was in the bucket of the large boom and attempting to load it onto the back of a flatbed truck when he was killed, said Officer Albie Esparza, a San Francisco Police Department spokesman.

The incident happened in a below-ground area of the Moscone South building on Third Street between Howard and Folsom streets, Esparza said. The man was declared dead at the scene. Most workers at the site were sent home for the rest of the day.

Jason Barnett, a spokesman for the Moscone expansion project and for Webcor Builders, the construction company working at the site, said the man was crushed.

A construction worker was killed in an apparent accident at Moscone Center Friday morning. Police said the man was in the bucket of a cherry picker when he was killed. A construction worker was killed in an apparent accident at Moscone Center Friday morning. Police said the man was in the bucket of a cherry picker when he was killed. Photo: Steve Rubenstein / The Chronicle / / Photo: Steve Rubenstein / The Chronicle / / Image 1 of / 7 Caption Close Construction worker crushed to death at Moscone Center 1 / 7 Back to Gallery

“We are saddened to report that a fatal accident occurred this morning at the Moscone Convention Center Expansion project,” Barnett said in a statement. “An employee of a heavy equipment rental company was fatally injured at approximately 6:45 a.m. this morning. The employee had come to pick up an aerial work platform also commonly known as a high reach boom at Moscone Center and take it back to the rental company. During the process of removing the machine, the man was crushed between the heavy device and a concrete structure.”

A spokeswoman for Cal/OSHA, the state Division of of Occupational Safety and Health, said the agency is investigating the accident. She identified the equipment rental company as Ahern. It has branches in 81 cities, with its South San Francisco branch located closest to the accident site. Calls to Ahern were not immediately returned.

Workers have completed about half of a $350 million expansion of Moscone Center that will increase its size from 1.2 million square feet to 1.5 million square feet.

Steve Rubenstein is a San Francisco Chronicle staff writer. Email: srubenstein@sfchronicle.com Twitter: @SteveRubeSF