The building collapsed when Lahore Development Authority (LDA) was carrying out an anti-encroachment drive in the area, said a Rescue 1122 spokesman.
The authority had issued a notice of the drive two days ago, however, the residents were not cautioned before the operation started.
On information, Rescue 1122 staff and other rescue teams reached the spot and started a rescue operation which continued for five hours. They removed the debris, pulled out the injured workers and rushed them to Jinnah Hospital where three of them expired.
The identity of the dead was yet to be determined.
The injured have been identified as Abdul Rehman, Munir, Fakhar, Sardar, Nadeem, Afzal, Azhar, Saeed, Khadim, Muhammad Yar, Yaseen, Muhammad Hussain, Ashraf, Ahmad Yaar, Naveed, Mushtaq, Yousaf, Muhammad Naeem, Qasim, Yameen, Muhammad Nadeem and Kashif.
Copyright APP (Associated Press of Pakistan), 2011