No injuries were reported in any of the three collapses, and investigations would begin after the storm cleared, officials said.
Soon after one of the cranes collapsed, the chief executive of the company developing the building told Reuters he was attending the U.S. Open tennis tournament in New York when the accident occurred and had just learned about it.
"This particular crane, some of it was taken down," Jorge Perez, chief executive of The Related Group, Miami's largest developer, said by telephone. "They were surprised that it went down because they felt it was one of the more secure cranes, so we're right on it."
A crane at a Related Group project in Fort Lauderdale went down later on Sunday, Perez said. He had no immediate details about the incident.
High winds also snapped the boom of a crane erected on top of a Miami apartment building under construction. The project was being developed by New York-based Property Markets Group, according to The Real Deal, a South Florida real estate news website.
After the collapse, the boom was partly dangling on the side of the building, attached to the crane tower by a cable, photos on Twitter showed. Attempts to reach Property Markets Group offices in New York and Miami were unsuccessful.
Miami had been in touch with Perez, but the state of Florida and the U.S. Occupational Safety and Health Administration had jurisdiction over the cranes, City Manager Daniel Alfonso said. No one was immediately available to comment at OSHA or the governor's office.
The National Weather Service recorded wind gusts in Miami reaching about 100 miles per hour (160 kph), with sustained winds of 50 to 60 mph (80 to 96 kph), as Irma moved up Florida's west coast.
As Irma approached last week, Miami officials said 20 to 25 construction cranes were up across the city and that they were designed to withstand winds of 145 mph (235 kph).
It warned that the cranes had to be unpinned, so that their horizontal booms could rotate on their support columns like a weather vane.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)