Richard Williams starting working at the Alfred P. Murrah Building the day it opened in 1977 in downtown Oklahoma City.

He was there April 19, 1995 when a bomb ripped through the building killing 168 people including 19 children.

It's been 20 years since the attack and Williams still wants to make sure people don't forget the horror of that day.

“That’s exactly what it’s about. Never forget,” Williams said.

Williams was the building manager and worked on the first floor.

Timothy McVeigh parked the Ryder truck with the bomb about 75 feet from Williams’ desk. He was talking to a coworker when the explosion happened.

“That’s the last thing I remember. I was buried under rubble like so many were,” Williams said.

Williams said Officer Terry Yeakey pulled him out and then came back for him.

“He came back in and dug me out and carried me out of the building. He’s a hero pure and simple,” Williams said.

A year later Yeakey committee suicide. It was a week before he was supposed to received an award for saving lives on April 19.

“In my opinion he was another victim,” Williams said.

After the bombing Williams testified in four trials including McVeigh’s. He said that he doesn’t hate him.

“Hating serves no purpose. That’s what those people do. I will never forgive him. I’ve never been able to do that,” Williams said.

He’s also served on numerous committees and helped open a memorial and museum.

“That process was cathartic for me and part of my healing to get involved,” Williams said.

He said that 20 years later is still learning about what happened that day.

“I learn something new every day. I don’t understand it and I’ll never understand,” Williams said.