MINNEAPOLIS (AP) — Concrete barriers and chain-link fencing are going up around the site of the Super Bowl in downtown Minneapolis, where a contingent of local, state and national agencies is working to ensure that the game and dozens of related events are safe.

The downtown location of the Feb. 4 title game has presented challenges for authorities, who have had to get creative as they carved a secure perimeter around businesses and a major hospital near U.S. Bank Stadium. But it's not the first time the Super Bowl has dealt with the challenges of a city center, and authorities who have spent roughly two years thinking about every possible scenario say they are prepared.

"We're ready for anything that may come our way," Minneapolis Police Commander Scott Gerlicher said. "It's about not just feeling safe, but making sure people are in fact safe."

Gerlicher, whose department is overseeing security, said this Super Bowl will have the largest deployment of federal resources yet. That's because Minneapolis has a relatively small department — less than 900 officers compared with the roughly 5,000 in Houston, where last year's game was held — and needed more personnel.

Dozens of other cities are sending officers too, and the Minnesota National Guard has been activated. An additional 10,000 volunteers are being trained to spot suspicious activity.

Visitors can expect to see increased police patrols, bomb-sniffing dogs, helicopters, officers in tactical gear, and that chain-link and concrete fence around U.S. Bank Stadium.

Plenty of technology such as motion detectors, closed-circuit cameras and air particle sensors will be operating behind the scenes. Giant machines are being used to scan shipments to the stadium. Extra security cameras will be sprinkled around the city, and NFL-sanctioned events will have metal detectors. Teams will be in place to react to whatever comes up.

"Our efforts are to make sure that it's a warm and inviting atmosphere. But make no mistake about it — there are tons of watchful eyes from the law enforcement and public safety sectors," said Alex Khu, special agent in charge of Homeland Security Investigations in Minnesota and the federal coordinator for this year's Super Bowl.

Because of the dense area around the stadium, some security screening will be happening off-site. They also had to figure out how to secure Super Bowl Live, a largely free-flowing, 10-day outdoor event that's open to the public. Meanwhile, some events are being held in nearby St. Paul and at the Mall of America in Bloomington, while team hotels, practice facilities — and transportation to and from — also must be secured.

Jeffrey Miller, former senior vice president and chief security officer for the NFL, said each host city faces different challenges. In Minneapolis, perhaps the biggest is the weather. He said security staff may need to be doubled or tripled to keep people from being exposed to dangerous elements for a prolonged time.

"That's a challenge, and it's a costly one you don't have if playing in San Diego," he said.

Miller said setting up a perimeter around a downtown venue is more difficult than setting one up around a stadium surrounded by parking lots. Architects, engineers and other experts are part of the planning. For fans, he said, there are advantages to being downtown and close to the action.

"The NFL is really good at trying to balance security needs with the fan engagement part of the equation," he said.

Miller said officials also have to take into account recent world events — meaning the possibility of a terror attack.

Joe Rivers, assistant special agent in charge of the FBI in Minneapolis, said a threat assessment for the game has included analyzing attacks around the world. He cited the May bombing of an Ariana Grande concert in Manchester, England, the Oct. 1 shooting at an outdoor concert in Las Vegas and the Oct. 31 vehicle attack on a New York City bike path. Without providing detail, Rivers said authorities used those attacks to shape their plans.

Local history must also be considered. Minneapolis has seen dozens of young men travel to Somalia or Syria to join extremist groups over the past decade. There also has been a stabbing attack at a central Minnesota mall and a more recent bombing of a local mosque.

"It's impossible for us to ignore the historical cases that we've had here and the type of threats ... that we've addressed," Rivers said.

He said there is no credible threat to the Super Bowl, and authorities are continuing to gather intelligence. Rivers said his main concerns are low-tech threats, such as someone driving a vehicle into or firing a weapon at a crowd.

"Not to alarm anyone, but it's not hard to come by weapons in this country and with where our venues are located and things like that, there's no way we can possibly secure every single floor of every single building that can see a venue or can overlook a crowd, so those are concerns, yes," he said.

Fans attending Super Bowl events can help by staying vigilant. In addition to calling 911, people who see something suspicious can call 1-800-CALL-FBI. In the event of something like the Boston Marathon bombing, the FBI has created a website where witnesses can upload videos and photos so the FBI can gather evidence quickly.

"Obviously, the best case scenario is that we hope that we do all of this ... and no one never even realizes all the legwork that went into it on the front end," Rivers said. "They just show up, have a good time, and leave and go home."

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