THORNTON, Colo. -- Walmart is American as apple pie.
On Wednesday night, another American staple became the center of gun violence when police say a man walked into a Thornton store and randomly killed three people near a cash register.
Soft targets such as a Walmart have been under threat of random attacks for years. They have few exits and usually hundreds of people are inside.
"Walmarts have greeters but no armed guards," said Grant Whitus, a security expert who was on a SWAT team that responded the day of the Columbine shooting.
"Any location where you have people close together is considered a soft target."
"My belief is these places, these locations where you are going to have a lot of patrons should hire an armed guard to protect them."
If there is a random shooting, Whitus advised running first and if necessary, fighting back.
But for this shooting, Chris Short said he had no time to run.
"I couldn't run, I couldn't run fast enough," Short said.
While he hid under a nearby cash register and was scared, he said he was not surprised.
"The way things are going any more just seems like it's being an everyday thing," Short said.