Director Tony Chan says that all the actors who play firefighters underwent a 100-day-long training to master firefighting techniques, including quickly putting on firefighter gear and navigating smoky rooms.

“I appreciate the effort of all the actors and actresses. Most of them agreed to join the movie even without reading the script as they believed it’s a worthy cause to recreate the heroes’ story on screen,” says Chan.

“They had to do rigorous training in hot weather. Many actors nearly suffered heat stroke but they persisted and insisted on performing the stunts without using stand-ins,” adds Chan.

The film held a sneak preview on July 28.