LAS VEGAS — Even while portions of the Las Vegas Strip remained an active crime scene for the worst mass shooting in modern U.S. history at the Route 91 Harvest Festival, there were signs that life was returning to normal in this tourist destination, the self-billed “Entertainment Capital of the World.”

Tourists still in town for the week did their best to avoid the area, but many couldn’t help but stop and take pictures of the police presence near the Mandalay Bay where 64-year-old Stephen Paddock fired on a crowded concert below, killing nearly 60 people and wounding more than 500.

On the north end of Las Vegas Boulevard, the largest gambling convention in the country — the Global Gaming Expo — was under way as planned Tuesday, offering attendees a preview of the latest casino games and technologies. Hotel staff, bell hops, valet drivers, blackjack dealers and others who keep the tourism machine running meanwhile reported for work as usual — albeit under the pall of a massacre that claimed the lives of people enjoying one of the many live, outdoor events hosted here every year.

More than 42 million people venture to Sin City each year, flocking to its casinos, nightclubs, convention centers, as well as indoor and outdoor concerts. Local police and hotel security have trained for just about every scenario imaginable, but Sunday proved to be an unimaginable one: an active shooter firing from a building high above the venue he was attacking.

“Nothing of this scale has ever happened in Las Vegas,” said David Schwartz, director of the Center for Gaming Research at UNLV. “We’d have to know a motive before we can figure out how to prevent it.”

The last time the city saw a steep drop in visitors was immediately after the 9/11 terrorist attacks, but even that was temporary, Schwartz said. After the 2002 bombing of a Bali night club that killed 202 people and injured 200 more, tourism from Australia slowed but eventually rebounded. Similarly, New York City continues to be a vibrant tourist destination, Schwartz said.

“We’ve seen the history of places bouncing back after a thing like that,” he said.

Entertainment and tourism is the lifeblood of a city where the leisure and hospitality industry employs nearly 300,000 people, or roughly a third of all payroll jobs, according to recent estimate by the Bureau of Labor Statistics.

Vulnerable to economic downturns and more modern fears like terrorism, Las Vegas marketers managed to breathe new life into the city after the 9/11 attacks, unveiling a rebranding that would become so successful the effort would eventually enter the American lexicon: “What happens in Vegas, stays in Vegas.” The slogan effectively cast Las Vegas as a city where anything goes, giving visitors license to indulge in the brightly-lit 24/7  bacchanal of booze and gambling without a care.

Las Vegas tourism officials declined to comment on how the city might respond to potential safety concerns by tourists. In a statement, Rossi Ralenkotter, CEO of the Las Vegas Convention and Visitors Authority, called the shooting a “horrific, yet isolated event. At this time, it is important to allow the Las Vegas Metropolitan Police to conclude their investigation into the incident and to attend to the needs of the victims and their families. Las Vegas is a strong community that will work through this tragic incident.”

Two hotels, the Wynn Las Vegas and the Encore began checking guests’ and visitors’ bags with handheld metal detectors on Tuesday.

Long considered “soft targets” by security experts, hotels will likely be cautious about proposing stricter security standards, particularly ones that might be overly visible to tourists, some experts said. But considering the sophistication of security operations at many casinos, some security enhancements could be invisible to most visitors.

“From the people I’ve spoken to, (casinos) have made huge investments in security, said Steven Carvell, a hospitality professor at Cornell University. “We just don’t see them. That’s part of the art form.”

Indeed, most casinos are heavily monitored by surveillance cameras, and hotel security forces resemble small police departments. But with so many entry points, it would take “a huge amount of effort to ensure the safety of their guests without interrupting their pleasure.”

Stephen Barth, a University of Houston hospitality professor, said tourism officials will have to consider how to reassure tourists their safety is ensured while at the same time considering ways to improve security.

“It’s a constant battle for hotel to balance guest privacy and the guest experience with safety and security,” Barth said.

Some tourists and others visiting the city’s attractions said they want to see baggage screened by hotels when guests check in. Many demanded to know how Paddock managed to bring nearly two dozen firearms into his room without notice.

But even that is highly plausible, particularly at a hotel such as Mandalay Bay, home to one of the city’s largest convention centers, Barth said.

“There’s a lot of packages or bags or exhibit items being moved in and out,” he said. “It’s not unusual for people to have lots of things stacked up in their rooms.” The hospitality expert noted that housekeepers are not trained to go into people’s bags, but to respect the privacy of guests.