LAS VEGAS >> As volunteers streamed in to donate blood, doctors tended to the wounded and investigators scoured the scene of the deadliest mass shooting in modern U.S. history, Las Vegas tourism officials moved quickly to protect their valuable franchise in a city where branding is everything.

“What happens here, stays here,” the official slogan advertising agency R&R Partners developed in 2002, with a wink to naughty behavior, no longer seemed appropriate after the Oct. 1 attack that killed 58 people.

The city put that motto on hold, and the public agency charged with marketing Las Vegas went to work creating a new pitch for the tourist destination.

Initially, it unveiled messages that focused on how the community came together after the mass shooting, with average people joining first responders in helping victims.

A spot featuring a cityscape and the voice of Las Vegas native and retired tennis star Andre Agassi won praise for its sensitivity. “What is strength?” Agassi asks, playing off the #VegasStrong slogan that exploded on Twitter. “Strength is valet parkers who become medics, mothers who become emergency responders.”

The response has been more mixed to the TV ad that followed, showing just how difficult it can be for organizations to hit the right tone after a deeply tragic event. It also underscores how a message that resonates with fans can fall flat with others.

That spot – shown nationally starting late last week on networks including ESPN, Fox Sports, Bravo, TNT, The Weather Channel and Travel Channel – features real-life social media messages posted after the shooting.

“NO ONE and NOTHING will stop me from going to Las Vegas,” reads the first message.

“Will be there in 5 days,” writes another Las Vegas fan.

Paul A. Argenti, a Dartmouth College professor considered a pioneer in corporate communication, said he was taken aback by the advertisement, which he saw during a televised sports event.

“It’s a little too tacky to continue to promote tourism” two weeks after the attack, he said. “It’s really something for three months down the line.”

Argenti said organizations risk consequential mistakes if they don’t carefully consider messaging after tragic events. British Petroleum, maligned for its clumsy handling of the Deep Horizon oil spill in 2010, continued ads touting its “green” record because they were already paid for, he said.

Instead of national advertising, Las Vegas should consider “hypertargeting” people most likely to return, focusing on fun and excitement while avoiding even subtle reminders of the shooting, said Eric Schiffer of ReputationManagementConsultants.com, which specializes in cleaning up reputations.

“People move away from pain much faster than they move toward pleasure,” he noted.

Top officials with R&R Partners and the Las Vegas Convention and Visitors Authority said they were certain their most recent ad hit the perfect pitch, and seemed surprised it raised eyebrows.

The posts they chose featured people “speaking out with their hearts,” said Rossi Ralenkotter, the authority’s president and CEO.

Ralenkotter likened the fan’s insistence on returning to Las Vegas to people who won’t let fear change their lives after a terrorist attack.

“If you look at the social posts out there, there are a lot people saying things just like that,” said Arnie DiGeorge, executive creative director for R&R Partners. “That’s a pretty universal statement.”

“#VegasStrong” billboards and images of people donating blood were also recently included in a video assembled by a coalition of southern Nevada government officials and economic development agencies to demonstrate the city’s resilience while promoting the region as a potential site for Amazon’s second headquarters.

Las Vegas’ rebranding began shortly after a gunman on the 32nd floor of the Mandalay Bay hotel casino opened fire on a country music festival below.

The visitors authority, charged with delivering nearly 43 million tourists to Las Vegas annually, quickly brainstormed with its ad agency for a new message to keep Las Vegas out front in a tasteful way.

“We felt it was still important for the town to have a voice,” DiGeorge said.

MGM Resorts International, owner of the Mandalay Bay, also immediately shelved a slogan it unveiled weeks before: “We are not in the hotel business … we are in the holy s — – business.” MGM changed its digital signs to #VegasStrong, and in his first public address after the attack, Chief Executive Jim Murren urged convention organizers to keep believing in the city.

Electronic billboards along the Strip that typically promote restaurants, concerts and a topless pool broadcast a phone number victims and their families could call to reach an assistance center. They expressed appreciation for first responders, casino employees and visitors.

“We’ve been there for you during the good times. Thank you for being there for us now,” one billboard message read.

After digital marquees throughout the city were briefly dimmed to honor victims, another new slogan appeared: “When things get dark, Vegas shines.”

Retailers jumped in, selling #VegasStrong T-shirts for $18.75 in airport gift shops. Proceeds from the shirts will go to an official fund to benefit victims, a shop salesman said.

In southern Nevada, where statistics show the leisure and hospitality sector accounts for nearly one-third of the workforce, government officials also embraced rebranding.

Clark County Commission Chairman Steve Sisolak, a Democratic candidate for governor, told reporters soon after the massacre it would be officially referred to as the “1 October” event. News releases and other county communications adopted that language, omitting the word “shooting” and calling it an “incident.”

Haemoon Oh, dean of the College of Hospitality, Retail and Sport Management at the University of South Carolina, said he has no doubt the city will recover as long as it focuses on healing and refrains from aggressive marketing.

“One distinct characteristic of the hospitality and tourism people and industry is resilience,” he said. “The city will rebound, and people will regroup stronger.”