A team of 2 subcontractor workers was installing insulation material on piping in the top slab level inside A60 shaft of a concrete base structure. It is believed that one of the workers decided that he needed a board to use for cutting or storing of insulation material. The worker saw a 9 mm plywood board lying on the floor, picked it up on one side and started to shake off sandblasting grit from it. As he was lifting the board (approximately 10 kg) he made a step forward and fell into a manhole in the floor that the board he removed was covering. He fell into the 3 foot (1 m) diameter hole, falling about 40 feet (12 meters) down to a concrete floor and hitting some piping on his way down. The worker received fatal injuries and died in the ambulance on the way to hospital. The worker died due to severe injuries.