Three people were killed Thursday after a computer and electronics mall caught fire in downtown Harbin, capital city of the northeastern province of Heilongjiang, firefighters said. Witnesses said the fire broke out and fiercely spread through the top floor of the six-floor Nantong Computer Mall which houses shops and booths selling electronic products and parts as well as many logistics companies. Three construction workers working on the top floor were killed while hundreds of vendors and customers managed to escape the burning building, according to China\'\'s News Agency (Xinhua). The building\'\'s newly-added top floor was illegal as the mall had not obtained permission from local authorities to build it, said the firefighters. The cause of the fire is under investigation.