That is why safety training is important, now they know; and don't have to wait for an accident to happen.
Brasilia, Brazil - Moment zip wire SNAPS sending thrillseeker plummeting 20ft down to the road below
The shocking incident took place in Brasilia, Brazil, as the man, who has not been named, endured a horror freefall.
The victim had been taking part in a firefighters' safety course in the neighbourhood of Asa Sul, which involved descending from the first floor of a building to the pavement using the zipline.
Footage shows the man, who appears to be nervous as he edges along a windowsill, releasing himself off the building while tied to cables and ropes.
But as he descends using the zipline, one of the wires appears to break and he falls about 20ft onto the pavement below.
Onlookers are heard screaming as he falls with what appears to be a loose safety rope behind him.
He was taken to Base Hospital conscious, with pain in his left arm, ribs and a cut on his head.
One of the man's colleagues told local media that after the accident on January 27, he has since been discharged from hospital and is recovering at home.
The Official Alpha-Resgate school, responsible for the course, which was closed after the accident, told local media that the coordinators and instructors provided first aid to the student.
They said: "The course coordinator and all the instructors gave full support to the student, we did all the first care in the same way!
"We called the firefighters and waited. The coordinator went with him to the hospital entrance and to the medical centre.
The shocking incident took place in Brasilia, Brazil, as the man, who has not been named, endured a horror freefall.
The victim had been taking part in a firefighters' safety course in the neighbourhood of Asa Sul, which involved descending from the first floor of a building to the pavement using the zipline.
Footage shows the man, who appears to be nervous as he edges along a windowsill, releasing himself off the building while tied to cables and ropes.
But as he descends using the zipline, one of the wires appears to break and he falls about 20ft onto the pavement below.
Onlookers are heard screaming as he falls with what appears to be a loose safety rope behind him.
He was taken to Base Hospital conscious, with pain in his left arm, ribs and a cut on his head.
One of the man's colleagues told local media that after the accident on January 27, he has since been discharged from hospital and is recovering at home.
The Official Alpha-Resgate school, responsible for the course, which was closed after the accident, told local media that the coordinators and instructors provided first aid to the student.
They said: "The course coordinator and all the instructors gave full support to the student, we did all the first care in the same way!
"We called the firefighters and waited. The coordinator went with him to the hospital entrance and to the medical centre.