Working like a jackhammer, a crane poked away at the concrete and steel structure while an excavator cleared away the debris. It was sorted for recycling, said Robbie Lyng, the school district's senior construction project manager, at the site.
The section of the gym that housed locker rooms and offices had already been torn down by Wednesday morning. The demolition was due to be fininshed by the end of the week.
A little piece of history came down with the old gym, which has been a part of the school since 1950.
"It's an end of an era," said district spokesman Terry Koehne. "But, we obviously always err on the side of safety."
When the large old gym underwent seismic testing in February it was deemed unsafe for a major earthquake - the concrete structure would be liable to crumble - and shut down immediately.
The school's smaller and even older gymnasium, built in 1940, will also be torn down, early next year. The new large gym will be built in its place.
The new gym is expected to cost between $7 million and $8 million and will be similar in design to the state-of-the-art facility at Dougherty Valley High School. Construction will likely begin next spring and be finished by fall 2010, Koehne said.
"I think there's a bit of melancholy around the gym being demolished after it stood for so long and had so much history and so many memories," he said. "But this is definitely a good thing for the San Ramon campus and the community."