A Pakistani official says the death toll from the collapse of a factory building last week has risen to 53.Jam Sajjad Hussain said Monday that rescuers have sifted through nearly all the debris from the collapse of a four-story building in the eastern city of Lahore.Rescuers have retrieved 100 living workers from the rubble, including a teenager whose family assumed he was dead.The cause of Wednesday`s collapse is yet to be determined.The building caved in a week after a powerful earthquake in neighboring Afghanistan killed nearly 400 people in both countries.