In San Juan, Puerto Rico, the Dupont Plaza Hotel, once located in Condado where the Marriott currently stands, experienced a devastating fire on December 31, 1986. The fire, set by three employees, originated on corrugated cardboard cartons of furniture, containing mainly dressers composed of particleboard and wood, located in the south ballroom. The fire rapidly broke out of this space and swept through the lobby and casino areas. As a result of this fire, 97 people died in less than 12 minutes.

It is believed that the occupants of the lobby and the casino first became aware of the serious threat to their lives with the crash involved in the breakage of the windows located between the south ballroom and the foyer. This window breakage occurred at the time of flashover, allowing a flow of dense smoke into the lobby.