NEW YORK (CBSNewYork/AP) — More than a half million fans over two weeks are expected at this year’s U.S. Open tennis tournament, which begins Monday in Flushing Meadows, Queens.

Security officials are ramping up efforts to make the grounds safer than ever for the event.

Authorities this year fortified fencing near a grandstand stadium at the Billie Jean King National Tennis Center so it can withstand a crash from a car bomb.

Security director Michael Rodriguez, who oversees a private security force of 300 officers, said that’s one of many measures aimed at protecting the event.

He is expecting a larger-than-usual show of force this year from the NYPD in the wake of attacks in Europe and mass shootings in the United States.

“A lot of this stuff is off the radar, but it goes back to what’s happening in the world,” Rodriguez said during a flurry of last-minute preparations for Monday’s opening matches.

Officials say they know of no credible threats against a Grand Slam event that happens to end with the men’s final on the 15th anniversary of 9/11. But the NYPD, which ordinarily has hundreds of officers in and around the tennis center, plans to increase its presence this year. That’s on top of the tournament’s private security guards.

Layers of protection include installation of temporary closed-circuit surveillance cameras, including some perched atop the 23,771-seat Arthur Ashe Stadium, along with devices to detect chemical, biological or radiation risks.

“I’ve already warned people they’re going to see it,” Rodriguez said of the extra security. “And they should feel good about seeing it.”

Just outside the gates of the tennis center, the NYPD will keep heavily armed officers trained to respond to terror attacks at the ready. Counterterrorism police are outfitted in tactical gear, bomb-sniffing dogs are standing at the entrances and every vehicle that passes through the gates is inspected with cameras rolling.

As with other with other events like New Year’s Eve in Times Square, plainclothes officers will mix with the crowds.

Other defenses include strict screening checkpoints for the throng of spectators. In the past decade, the U.S. Open became among the first sporting events to prohibit backpacks and use airport-style, walk-through metal detectors instead of less-reliable wands to check people for weapons.

In addition, the event has a rigorous inspection system for the more than 1,600 trucks that make deliveries during the event. Drivers are vetted, given a bar code and directed to an inspection point deliberately located a quarter-mile from the tennis center before they can enter the grounds.

Arthur Ashe Stadium is also now covered by a retractable roof, which can close in under seven minutes. It’s a feature that protects from the elements and provides another layer of safety at the heavily guarded games.

Last year, a drone crash from above stopped play. A Brooklyn high school science teacher lost control of the aircraft while flying it in the sprawling grounds that surround the tennis stadiums.

But in a sport where fans have to be quiet, excitement now hangs in the air.

“Every rally is incredible so, you kind of have to maintain your composure,” one fan told CBS2’s Magdalena Doris.

“After a match is won or a game is won, I would scream,” said another.

About 700,000 people are expected at the U.S. Open this year.

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