Signs and message boards up and down the Strip — the planet’s brightest spot from space — were scheduled to dim or go dark to commemorate Earth Hour, a worldwide campaign intended to draw attention to climate change.

Lights shining on the hotels went dark, too, sending the Strip into an eerie darkness. Tourists looked up while sipping their beers and yard-long margaritas. Many whipped out cameras and cell phones to get pictures of the rare event.

John Hildebrandt, a 37-year-old mortgage broker from Las Vegas, came down to the Strip with several friends to see the event and support its message.

“I think it’s great,” he said. “They should do it every night for an hour.”

“We’re also taking note of what’s not off,” said 48-year-old Chris Miller, gesturing toward the Monte Carlo.

That hotel’s sign flicked off a few minutes later.

Las Vegas served as a flagship city for the worldwide event, and all of the Strip’s major resort operators planned to participate. More than a dozen off-Strip properties, including the Palms and hotels belonging to Boyd Gaming Corp., said they’d turn down the lights as well. Even the “Welcome to Fabulous Las Vegas” sign anchoring the Strip’s southern end was set to black out, as was the Fremont Street Experience canopy.

“It’s an opportunity for us to encourage other companies and individuals to do as our company has, and focus on sustainability and conservation,” said MGM Mirage spokesman Gordon Absher in a recent Review-Journal interview. “Having the skyline of one of the world’s most-recognizable cities go dark is one of the most dramatic statements the World Wildlife Fund could make.”

Ping Hsu, a 31-year-old manager at the P.F. Chang’s at Planet Hollywood, walked outside the restaurant to get a glimpse of the Strip skyline, the only lights from which came from construction lighting at CityCenter and various hotel rooms.

“I was thinking, ‘Are they really going to do it?’ And they did,” she said. “I’ve never seen it like this.”

Resort corridor hotels will dim their lights to remember various celebrities, including Frank Sinatra. The Strip went dark the night after his fatal heart attack on May 14, 1998.

One early participant in Earth Hour backed out of the event late.

Station Casinos had been in on initial planning sessions for the event and said it would turn down its lights, but Earth Hour ended up conflicting with the company’s Win a Million in March promotion, a series of major, multi-property prize giveaways scheduled to happen on the hour throughout Saturday night. Company officials decided they couldn’t carry out the prize event and Earth Hour at the same time.

The city of Reno was scheduled to darken its „biggest little city in the world“ arch.