The sheer force of the detonation reportedly wrecked around 200 properties
A total of 247 workers were operating underground
The explosion tore through the Huasheng Fireworks Manufacturing and Display Company
The sheer force of the explosion reduced parts of the building to rubble
President Asif Ali Zardari expressed condolences to the victims’ families
Authorities said the cause has not yet been determined
Investigators say bomb was planted under vehicle in apparent assassination