By Steve Large

SACRAMENTO (CBS13) — Law enforcement experts are scrutinizing how a mob was able to get inside the U.S. Capitol in Wednesday’s deadly chaos.

Retired California Highway Patrol Commissioner Spike Helmick oversaw security at the California State Capitol for a decade.

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“It’s just a tragedy,” Helmick said.

He watched stunned as the mob broke through doors and stormed the U.S. Senate floor. CBS13’s Steve Large asked Helmick how important it is for security to protect and prevent that from happening inside a legislative chamber.

“Oh, I think it’s priority number one,” Helmick said.

When Helmick was in charge of security at the California State Capitol, he says there was a big effort to keep access a priority, protecting the public’s right to protest.

“The one thing they kept saying, ‘do not make this a fort,'” Helmick said.

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More from CBS Sacramento:

Helmick says many subtle and undetectable security measures are in place in California’s State Capitol. Some were added after a fiery scene in 2001, when a suspect drove a big rig into the senate side of the building during a legislative session. The truck exploding into a fireball and the driver died.

“There was a hearing going on and they got out but they could’ve died,” Helmick said. “It just shows you how things can happen, for a variety of reasons.”

State investigators determined the driver of the truck was mentally disturbed, with a grudge against the governor.

Helmick says this violent scene at the U.S. Capitol Wednesday will lead to its own massive security review and new safety measures to prevent an attack like it again.

“Maybe this is a good wake up call,” Helmick said.

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The U.S. Capitol police department has 2,000 officers on its force. The Washington Post is reporting many of the Capitol police officers were in street clothes for this event and not riot gear.