Four workers were injured when the wooden scaffolding of a building under construction in Makkah's Umm Al-Joud District collapsed on Wednesday. Col. Ali Al-Muntashiri, director of investigations and spokesman of Makkah Civil Defense, said four rescue teams and two rapid intervention units rushed to the accident scene immediately after the operations room received an alert. The wooden scaffolding collapsed during concrete work on the ground floor of the two-story building. The collapsed portion measured about 12x6 meters. Al-Muntashiri said the four workers were standing on the scaffolding when it caved in. Civil Defense rescuers pulled out the injured workers who were trapped under the debris. Three of them suffered minor bruises and were treated at the site while the fourth worker was taken to King Abdul Aziz Hospital in Al-Zaher where he was given treatment and released. Investigations are underway to determine the cause of the accident. A committee comprising representatives of the Civil Defense, the Makkah municipality and neutral engineering offices has been formed to study the technical reasons for the collapse. __