A 23-story hotel on Miami’s exclusive Brickell Key was demolished Sunday morning in a controlled implosion that brought down the structure in under 20 seconds. The former Mandarin Oriental hotel collapsed around 8:30 a.m. following a series of rapid charges, marking the largest implosion for Miami in more than a decade. Spectators lined the waterfront across the bay at a safe distance to watch the planned demolition on the human-made island at the mouth of the Miami River.

“The demolition will make way for the groundbreaking of The Residences at Mandarin Oriental, Miami, a two-tower ultraluxury hotel and residential development scheduled for completion in 2030,” according to Swire Properties. The hotel first opened 25 years ago on Brickell Key, which sits across from downtown Miami. People watching the implosion safely from afar cheered and recorded phone videos as the building’s framework collapsed following the blasts.

Developers said the operation follows nearly two years of planning and coordination with specialized contractors and the city. “Implosion was selected as the safest and most efficient method to maintain the project timeline while minimizing disruption and ensuring the safety of the Brickell Key community,” developers said. Residents within 800 feet (244 meters) of the building were asked to stay inside their apartments during the blast with windows and doors closed.

The implosion happened a couple of minutes after what looked and sounded like blue- and pink-tinted fireworks were set off near the top of the building. Dust soon filled the air as building material crashed down, and some watchers wore face masks as they left the area. The demolition represents a significant transformation for one of Miami’s most exclusive waterfront locations.

Swire Properties’ new development will replace the single hotel structure with a two-tower complex combining ultraluxury hotel and residential components. The project timeline extends to 2030 for completion of The Residences at Mandarin Oriental, Miami. The controlled demolition method was chosen to minimize disruption to the surrounding Brickell Key community while maintaining construction schedules for the replacement development.