KARACHI: At least one person died and several received wounds when a portion of a residential building collapsed at Dua Chowk in New Karachi. The incident occurred due to gas leakage resulting in a powerful blast that razed the portion to the ground, according to the initial police inquiries. The explosion was so severe that the windowpanes of the nearby buildings also broke. Rescue teams reached the spot after getting information about the incident and started the relief work. The injured were taken to a nearby hospital, they said.