(Reuters) - Three men were killed in Florida on Wednesday afternoon when they fell nearly 1,000 feet after scaffolding collapsed at a television transmitting tower north of Miami, said an engineer of a TV station that uses the tower.


The men were removing gear at the top of the tower as preparation to install a new antenna when their support gave way, Steve Ellis, assistant chief engineer for Miami's WPLG-TV, told a reporter at the station.


The men were about 960 feet above ground - the height of a 90-story building - at the time of the accident, which a Miami-Dade Fire Rescue spokesman said occurred about 4 p.m. in Miami Gardens.


Earlier on Wednesday, a fire department official said initial reports were that the men were 300 to 400 feet above ground when the incident occurred.


The men were working for a Texas-based company, Tower King II, said Ellis, who added that the cause of the collapse was unknown.


Video shown on WPLG showed that the scaffolding extended from a crane-type device on the ground near the tower.

The antenna was being replaced for WSVN-TV, another Miami station that uses the tower for transmitting signals, Ellis told WPLG-TV.

The Occupational Safety and Health Administration will investigate the incident, WPLG reported.

Some 34 people in the United States were killed in television and communications tower incidents in the four years through 2016, according to OSHA's website.

(Reporting by Bernie Woodall in Fort Lauderdale, Fla.; Editing by Peter Cooney)