ARACHI, Pakistan — Fire ravaged a textile factory complex in the commercial hub of Karachi early Wednesday, killing almost 300 workers trapped behind locked doors and raising questions about the woeful lack of regulation in a vital sector of Pakistan’s faltering economy. It was Pakistan’s worst industrial accident, officials said, and it came just hours after another fire, at a shoe factory in the eastern city of Lahore, had killed at least 25. 
Flames and smoke swept the cramped textile factory in Baldia Town, a northwestern industrial suburb, creating panic among the hundreds of poorly paid workers who had been making undergarments and plastic tools.