“The alarm bleeped once,” says Michelle Gothan, senior marketing coordinator at the Scottsdale, Ariz.–based firm, “and then there was a message that the hotel was trying to determine the cause of the alarm.”

So the group of about 35 board members and company executives continued its meeting, which had begun two days earlier and was scheduled to end that day. But things took a much more serious turn about 10 minutes later, says Gothan, when, from the foyer outside of the meeting room, a woman screamed, “Oh, my God!”

It was at that point, says Gothan, relating the details as she heard them from her attendees (she booked the meeting but didn’t attend), that someone knocked on the door and told them to evacuate the building. That person escorted the group through the hotel’s executive offices (which were empty, Gothan says) and into the evacuation area. By the time the group got out of the hotel, most of the Monte Carlo had been evacuated and firemen were already battling a blaze that had broken out on the upper floors of the building.

The fire broke out around 11 a.m. PST. At the time, there were about 6,000 employees and guests in the Monte Carlo, which is owned by MGM-Mirage. All were evacuated safely and no one was seriously hurt, although some guests and hotel workers were treated for smoke inhalation.

The fire apparently started on the rooftop façade of the hotel and spread down as far as the 27th floor of the 32-floor building. According to published reports, investigators are focusing on a welding project on the hotel roof. The hotel remains closed, and no reopening date has been announced. In the meantime, MGM Mirage officials say they’ve relocated over 100 meetings and events scheduled at the Monte Carlo to other MGM Mirage properties.

While everyone in her group got out of the hotel safely, Gothan says it was “an intense experience” for the attendees.

One spouse of an attendee was on the 20th floor of the hotel when the fire broke out and, because she was in the shower, failed to get the word that she needed to evacuate. “She turned on the TV,” says Gothan, “and at first couldn’t get any stations to come in and couldn’t figure out what was going on. Then she tuned in to CNN and saw that the hotel she was staying in was on fire! So she evacuated on her own. That was kind of scary. We’ve all heard about what happened at the MGM Grand [a fire at the MGM Grand Hotel and Casino in 1980 killed 85 people]. Most of the people who died there died from smoke inhalation, and here I have a guest spouse on an upper floor of the hotel who didn’t know there was a fire.”

Another attendee was staying in one of the rooms that apparently was damaged by the fire but had already checked out and had brought his luggage down to the meeting room that morning. In fact, many attendees had done the same and were forced to leave their belongings behind in the meeting room when they evacuated. That luggage ended up at the Bellagio later that night. The attendees met up at the MGM Grand and were later provided with a “debriefing” room at the Bellagio, where they were given food and drink, says Gothan.

Lessons learned? Gothan says that from now on she’ll make sure she has cellphone numbers and emergency contacts for each of her attendees. “After the fire happened and everyone got separated, it took longer than it should have to get everyone back together. So there needs to be a master list with cell and emergency numbers.”