NEW YORK (AP) -- Businesses around the country are reevaluating security after a brazen shooting at a New York City office building raised questions about what it takes to keep workplaces safe.

The attack on a seemingly secure building -- in a gilded part of Manhattan where the rich live in sprawling apartments and tourists window-shop designer stores -- has rattled workers and prompted managers to examine whether they are adequately protected.

"What should we be doing different?" clients are asking, said Brian Higgins, founder of Group 77, a Mahwah, New Jersey, security company that is among those getting peppered with an influx of calls. "How can we prevent something like this?"

The gut reaction of some companies, Higgins said, is to buy the latest technology and blanket their workplace in cameras. But, he cautioned, that's only only effective if paired with consistency and long-term monitoring.

"If you're going to add a security measure ... you have to make sure you maintain it," said Higgins, a former police chief who teaches security at John Jay College of Criminal Justice.

Four people were killed in the shooting Monday before the gunman died by suicide. Images of the shooter, toting a long rifle on a street in the biggest U.S. city, then terrorizing an office building, have companies desperate to do something to keep the scene from repeating.

"People are frightened, people are asking questions," said Dave Komendat, the Seattle-based chief security officer at Corporate Security Advisors, where calls are also spiking.

With the U.S. locked in a pattern of gun violence virtually unparalleled in the world, security firms are used to the rhythms of the business. While attacks at a corporate office are less commonplace, a major shooting or an attack on an executive focuses attention back on security for a time, before receding.

"Give it a couple weeks, a month or so, it'll go back," Higgins said of the increased call volume. "When security issues don't happen for a while and companies start reexamining their budget, security is one of those things that companies cut."

Gene Petrino, CEO of Survival Response in Coral Springs, Florida, has also seen an uptick in calls from potential new customers, but expects it to be fleeting.

"When things are calm it's seen as an expense they don't need right away," he said, "and then when a tragedy happens it's a priority again."

Petrino said companies can make changes that aren't intrusive like using cameras with artificial intelligence capabilities to identify weapons. Sometimes, it may just be a matter of improving lighting in a hallway or putting up convex mirrors to see around a corner.

"Everything doesn't have to be bulletproof and locked with security cameras everywhere," he said. "You don't have to be Fort Knox. You can have very basic things."

Michael Evanoff, chief security officer of Verkada, a building security company based in San Mateo, California, said technology like AI-enabled cameras to help identify threats have become even more important amid a shortage of guards.

"It's harder than many realize to find and retain trained personnel," Evanoff said. "That makes it even more essential that guards are equipped with technology that can extend their reach."

Security at 345 Park Avenue, the site of the shooting, included an off-duty New York Police Department officer working as a guard. He was among those killed.

Rudin, the leasing company that manages the building, did not respond to a query about when the building will reopen or whether new security measures will be implemented. No matter what, though, every workplace has vulnerabilities.

"The security team has to be perfect to 100% of the time," said Komendat, a former chief security officer for Boeing. "Someone like this just needs to be lucky once."