On Saturday May 6, 2023 a tragic event occurred at the indoor swimming facilities of the Gaylord Rockies Resort in Aurora, Colorado. The metal HVAC ducts and parts of the indoor pool air conditioning system suddenly collapsed, injuring at least six guests. Without warning the massive metal structure suspended over the swimming areas and deck came crashing down onto children and parents enjoying the resort’s indoor water park. Chaos and confusion ensued when the fire alarms sounded, black water gushed from above, and parents frantically searched for their children. Initial speculation by guests, emergency services, and reporters turned to a fault in construction or mold as a possible culprit. However, the underlying cause may turn out to be an unexpected, but inevitable end to a series of events.
First Reports and Speculation
Early reports indicated that a portion of the large metal ducts, 3 to 4 feet in diameter, fell from the roof supports into the swimming pool and hot tub spa. This type of hazard is not what is typically thought of when discussing water safety, but it certainly highlights the risk we take when we bring water into buildings. Some early speculation reported by local media suggesting that “black liquid” sprayed out when the ducts fell was due to mold build-up inside the ducts is not supported by posted videos. Rather, the “black liquid” can be seen spraying from the fire suppression lines that were suspended below the metal ducts and ruptured when the ducts fell. The stagnant water that sits within fire suppression lines made of iron normally becomes black due to the formation of iron oxide.
The Weakest Link
Investigators will most likely focus on corrosion of the metal supports and cables that held up the metal ducts. Swimming pools, hot tub spas, and other water park features are constantly treated with oxidizing chemicals, typically chlorine, in order to control waterborne pathogens. This is not only required by public bathing rules and regulations, but necessary to keep the recirculated water from becoming a microbial health hazard. Unfortunately, the oxidizing chemicals tend to corrode metals both in the water and materials in the surrounding indoor environment. The heavy-duty metal ducts were obviously designed to withstand the corrosive environment; however, it is possible that the cables, linkages, or supports were not. Which component may be found to be the “weakest link” that failed is yet to be determined, but the catastrophic failure of the system and resulting injuries are evident. The loss of business, damage to reputation, and inevitable litigation that follow such catastrophic events are just a part of this facility’s future.
Less than 5 years after being permitted (reportedly in 2018), the catastrophic collapse of this structure demonstrates the dangers and risks posed by indoor water features. In order to keep them from becoming a biological breeding ground of human pathogens such as Staph aureus, Pseudomonas, Cryptosporidium, Legionella pneumophila and others, these water features must be constantly treated with toxic and corrosive chemical disinfectants. Infections from waterborne pathogens can cause skin rashes, severe diarrhea, severe pneumonia and even death.
Danger Lurks in the Water
It is necessary to treat swimming pools, hot tubs, water slides, and splash-pads with chlorine or bromine disinfectants to control the pathogen Legionella pneumophila and prevent cases of Legionnaires’ disease. It is estimated that up to 20% of Legionnaires’ disease cases reported were associated with public spa pools, with a fatality rate of 11%. In 2018 the number of confirmed Legionnaires’ disease cases approached 10,000. If caught early Legionnaires’ disease can be treated with antibiotics, but symptoms are often ignored until hospitalization is required. In recent reports ~95% of people diagnosed with Legionnaires’ disease required hospitalization. Symptoms of Legionnaires’ disease include cough, shortness of breath, fever, muscle aches, headaches, chest pain, confusion or other mental changes, and severe pneumonia. Ultimately, respiratory failure, septic shock, and acute kidney failure pose the greatest threat to patients admitted to intensive care. The lung infection caused by Legionella bacteria can lead to severe illness, hospitalization, and death in 10% to 25% of those who contract the disease.
Legionella infections occur by inhaling water aerosols containing the bacteria from a contaminated water system or source. Hot tubs and heated spa pools are recognized sources of Legionella and are typically treated to prevent its growth with chlorine or bromine. Legionella does not spread from person-to-person like COVID or Tuberculosis. Legionnaires’ disease often infects individuals over the age of 50, people who are or were heavy smokers and immunocompromised individuals.
One-third of the outbreaks of swimming-related disease were associated with hotel pools and hot tubs between 2000 and 2014. Over 27,000 people became sick and at least 8 deaths were reported according to a CDC report. The use of chlorine and other disinfectants is absolutely necessary, and required by law, for us to enjoy public pools and hot tubs, but there are unintended consequences and side effects even when they are properly used. Some pathogens are chlorine-tolerant such as Cryptosporidium and Legionella pneumophila. However, most microbes are effectively inhibited by chlorine and bromine.
A Balancing Act
The trade-off is that chemical levels must be constantly monitored and maintained in a “safe, but effective range”. Too little can allow the microbes to grow and pose a health risk. Too much can cause respiratory, dermal, and eye irritation in swimmers. Worse yet, indoor air impacts from long term chemical treatment and its effects on people and the critical structures of the indoor environment are not usually considered or inspected by either public health inspectors or building code enforcement authorities. Damage due to the corrosive effects of chlorine is common in indoor water parks and swimming facilities.
While the Gaylord Rockies Resort incident is tragic, it should prompt indoor pool operators everywhere to immediately inspect for corrosion to critical equipment and infrastructure, and hopefully prevent another such event. Currently public pool operators rely upon chemical disinfectants to keep the water “safe” from microbial agents, but this approach carries a number of risks and trade-offs. Engaging a trained health and safety professional along with routine inspections by outside parties can help prevent similar tragedies in the future.
Image Credits
https://insidethemagic.net/2023/05/air-conditioning-unit-colorado-theme-park-incidents-th1/
The opinions offered do not reflect those of the Gaylord Rockies Resort or any parties involved in the design, construction, or permitting of the facility.