KARACHI, Pakstan (AP) — A gas explosion ripped through an apartment building in Pakistan’s largest port city of Karachi on Thursday, killing at least 13 people, including women and children, and injuring several others after part of the structure collapsed, police and rescue officials said. The explosion happened in a residential area of Karachi, the capital of Sindh province, local police chief Rizwan Patel said. Rescuers were still removing rubble to search for any survivors trapped under the