"I've never forgotten what it was like to first approach the building and think this was the mother of all disasters," Dr. Ben Ho of Oakland Search and Rescue said. "Not only was the devastation tremendous, but we had never seen an area where there were in fact children, America's Day Care Center, and 19 children were victims as well as the working adults."
As part of a search and rescue team from Oakland, Ho worked for days sifting through rubble, looking for any sign of life.
"As time goes on, you know the possibility of people being brought out alive diminishes rapidly," Ho said.
Despite all that was lost, some was gained in terms of knowledge and experience for rescuers.
"We did learn from it, we've changed the equipment that we carry in the cache, and we've changed our training," Jane Moorhead of the Livermore-Pleasanton Fire Department said. "And it makes us safer, which is important."
"We've improved the way we go into buildings, we protect our people," Ho said.
For those who lost loved ones in the bombing, the legacy of Oklahoma City is much different.
"It's all a blur, but it seems like it was yesterday," Rudy Guzman said. Guzman lost his brother Randy, a Marine captain, in the bombing.
"He was so kind to lots of people. He helped out around the community here in the Castro Valley area. I just want somehow to keep his name alive," Guzman said.
As he has almost every year, Guzman will travel to Oklahoma City for the anniversary.
"I will be going back every year, be there the 20th, the 25th, as long as I'm here, I'll be going back to Oklahoma," he said.