Saturday marks the 35th anniversary of the deadly fire at the MGM Grand hotel-casino in Las Vegas.

Eighty-seven people died that day, as the fire burned through the busy building and the casino’s HVAC construction did little to contain the smoke or flames.

Sheet Metal Workers union-affiliated organizations are using the occasion to note how far the fire prevention efforts have come in regards to HVAC construction system design.

“The MGM fire was a surprising lesson for many, and it reinforced my commitment and that of many others to continue working to improve fire protection,” said John Klote, a licensed professional engineer and smoke-control expert.

Klote was among the investigators on site at the hotel in the days after the Nov. 21, 1980, fire.

The tragedy made regulators and lawmakers take note of the dangers lurking in hotel HVAC systems, Klote said. Only some areas of the MGM Grand had sprinkler systems. Five months after the fire, a bill passed in the Nevada Legislature requiring sprinkler systems in all homes, motels, office buildings and apartments higher than 55 feet. Sprinklers were also required in showrooms and other large public spaces.

In 1980, fire and smoke dampers on the HVAC market weren’t airflow tested after installation. An HVAC construction system should shut down before the dampers close.

In the case of the MGM fire, that didn’t happen, Klote said.

“The ones I saw [at the MGM Grand] just didn’t close, and that was a big building with a lot of dampers,” he added. “Dampers are much better now. You have to ask yourself, ‘What is the actual cause of them being better?’ There’s not a direct cause and effect, but you have to believe (the MGM fire) had something to do with it.”

The county fire department’s investigation said the hotel’s HVAC system dampers that served the casino were “bolted in such a manner to make them inoperable” and “products of combustion were distributed through the tower by the HVAC equipment.”

Today, sheet metal works students learning ductwork fabrication and HVAC market system design also learn about fire safety. Officials with Local 359 of the International Association of Sheet Metal Air, Rail and Transportation Workers in Phoenix invite fire chiefs and inspectors to educate them about the importance of fire and smoke damper inspections.

The union-affiliated National Energy Management Institute Committee works with the International Training Institute — also affiliated with the Sheet Metal Workers — to get contractors certified in fire life safety.

“If contractors have workers with certifications, they can get work,” said Chuck Holt, the energy management institute’s administrator. “Certifications are free to contractors, free to the workers.”

Bernie Brill, executive director for Sheet Metal and Air-Conditioning Contractors’ National Association Mid-Atlantic chapter, which employees union workers, said he didn’t initially realize the value of the program.

“When I learned about this, I realized this is something that can really save lives,” Brill said. “I was dumbfounded people conduct inspections of extinguishers and alarms but are not looking at dampers.”