Hundreds of people had to be rescued by firefighters on Wednesday after one of Hong Kong's tallest skyscrapers had caught on fire. Some office workers at the Hong Kong World Trade Center fled to the building's rooftop and became trapped during the fire.

Those on the lower floors were trapped in open-air areas where they awaited rescue. Firefighters used extendable ladders to reach the dozens that were trapped. According to officials, firefighters rescued a total of 770 out of the burning building. Around 40 people were reportedly able to escape on their own.

At least 176 firemen were dispatched to the scene by the fire department. Two breathing apparatus teams and two water jets were also dispatched to assist in the firefight. By 3:06 p.m. local time, authorities announced the fire had been brought under control.

Officials said at least 13 people had to be sent to the hospital for treatment of injuries, including smoke inhalation, sprains, and minor burns. Firefighters said the blaze started sometime during the lunchtime rush within the 38-story building, which is located in Hong Kong's popular Causeway Bay shopping district. The building mainly houses offices and a large shopping mall on the lower floors.

 An initial investigation found that the fire may have spread from the building's first two floors, where a large mall was undergoing renovations. Authorities believe the fire may have originated from the electrical switch room located on the first floor, which then spread to the scaffolding surrounding the lower floors.

The fire alarms and fire suppression systems, including auto sprinklers, smoke detectors, and manual alarms, on those floors, were reportedly turned off while the area was being renovated. Authorities said they still need to conduct further investigation to see if any fire safety regulations were violated by the building's contractors.

The building's owner, Sun Hung Kai Properties, said its service center promptly supported emergency crews in evacuating tenants and customers. It extended condolences to tenants who had been affected by the incident.

Ng Yau-Sheung, a senior divisional officer from the Fire Services Department, said firefighters were having difficulties in locating stranded tenants because of the building's large floor area.

Ng said it was also difficult to navigate the building because of the renovations. Officials said there were only two ways in and out of the building because some sections on the lower floors were blocked off. The number of elevators in service was also halved because of the renovations. Some escalators in the mall area were also turned off, with witnesses saying that it was "like a maze" for those who are not familiar with the building's layout.