IRVING (CBSDFW.COM) – The investigation and waiting game continues more than 24 hours after dozens of vehicles were crushed in an Irving parking garage collapse.

There are also concerns a domino effect could completely level the garage that has already partially collapsed – twice. More than 20 vehicles were crushed when the initial collapse happened just before lunchtime on Tuesday.

People who park at the the O’Connor Ridge Office Park, not far from Highway 114 on Fuller Drive in Las Colinas, tell CBS 11 News they’ll be parking elsewhere and will be shuttled to the buildings where they work.

irving garage collapse 2 Partially Collapsed Irving Parking Garage Will Have To Be Torn Down

(credit: CBSDFW.COM)

The garage provides parking for several professional offices. Initially, anyone with a vehicle parked farthest from the collapse was taken, one-by-one with a firefighter, to drive their vehicle from the garage. But eventually, the entire structure was locked down.

The garage remained blocked off Wednesday morning. Officials say it’s too unsafe to retrieve the dozens of undamaged cars.

Michael Ann Guthrie was one of the lucky few able to retrieve her vehicle, but said the incident disturbed her and her co-workers. “It’s frightening,” she said. “A lot of our girls were very upset, I think just because of being that close to it. We sent most of our staff home yesterday.”

Many people who weren’t able to get their vehicles out of the garage on Tuesday used Uber to make their way to work today.

Part of another level of the garage caved in — as Chopper 11 flew overhead — about five hours after the first collapse. There are fears the structure will keep crumbling, so officials with the Irving Fire Department say the garage will have to be brought down.

The garage provides parking for several professional offices. Initially, anyone with a vehicle parked farthest from the collapse was taken, one-by-one with a firefighter, to drive their vehicle from the garage. But eventually, the entire structure was locked down.

The garage remained blocked off Wednesday morning. Officials say it’s too unsafe to retrieve the dozens of undamaged cars.

Worker Santana Hightower’s car was among those totaled. She says the she and others have had concerns while driving in the garage. “It shakes,” she said. “Like, when you drive by you know you can feel it… boom, boom, boom, boom, boom. But I thought it was just normal, like an elevator. I never in a million years thought this would happen.”

James Vaughn also works in the area where the garage collapsed. He said, “I’ve been parking on this garage for five years and I’ve always thought that it was less than good and now it’s really clear that it’s had problems.”

Fire investigators haven’t determined what exactly caused the collapse but say the ground shifting a foot over the last six months likely contributed.

It didn’t take long after the initial collapse for Irving Assistant Fire Chief J. Taylor to confirm that no one had been inside the garage when it came down and no one was injured.

But the thought of what could have happened has left some office workers, like Tammy Stack, shaken. “We have probably about 15 employees who at different times during the day, will walk the garage or go out with weights and work out at lunchtime or after lunch,” she said. “So, there’s normally always someone in that garage, since it’s covered.”

The Occupational Safety and Health Administration (OSHA) is assisting the Irving Fire Department with the investigation as to the cause of the collapse.