The aftershock felt following terrorist attacks on September 11, 2001 reached the front door to one of Minnesota's most visited destinations.
With over 40 million visitors each year, the Mall of America has spent the last two decades revolutionizing security plans that were put to the test in the days, weeks, and months following the attacks on America.
"9/11 changed everyone's lives, not just mine or the Mall of America's, but it completely changed the way we look at threats," said Will Bernhjelm, Director of Security at the Mall of America. "The threat was no longer one dimensional."
Officials opted to not open the Mall of America on September 11, 2001 after the second plane hit the World Trade Center. In the following days, noticeable security changes were implemented including increased security at each door.
Those immediate changes led to long term changes that remain in place today.
"Our department changed drastically after 9/11 and one of the things we added right away was a K-9 program," Bernhjelm said. "That program started with one K-9 and now it's a lot more robust."
The make-up of Mall of America police officers also developed. Today, the mall employs plain clothes officers along with behavior detection officers, who look for suspicious behavior in people, objects, and vehicles.
"They work hand-in-hand with our K-9 staff," added Bernhjelm.
Training procedures have also evolved with the enhanced security measures.
Bernhjelm, who was training at Camp Ripley with the Minnesota Army National Guard on 9/11, says he was provided two weeks of classroom training and then 3-5 weeks of field training before his first solo shift.
"Now, officers go through a month-long classroom, and then they're paired with a senior officer for 2-3 months," he said. "By the time they ever take a call by themselves, they have over 500 hours of training which is far above and beyond the industry standard."

The Mall of America's security enhancements have been a way to address how threats have changed since September 11, 2001.
Immediately after 9/11, Bernhjelm says the focus was terrorism and that today, the threat has evolved to a much broader scope due to technology, social media, disorderly youth, or organized retail crime.
"We're trying to prepare our staff to handle anything and everything."
Bernhjelm says all of the measures in place are solely to thwart off any threats before they reach the millions of guests who descend on the mall yearly.
"We have programs that were developed as progressive programs where we're not just waiting for something to happen," he said. "We're trying to go out and stop it before it happens. That's kind of a newer approach in the last 20 years, which is kind of sad to say. It probably always should've been that way, but 9/11 kind of woke everybody up and changed the way we thought about how we protect this building."