Rescuers worked in frigid cold to reach 21 miners trapped underground Sunday as the death toll from a huge gas explosion in a northern Chinese mine jumped to 87 _ the deadliest blast to hit the beleaguered industry in nearly two years, AP reported. The pre-dawn blast Saturday at the state-run Xinxing mine in Heilongjiang (pronounced HAY-long-jeeahng) province near the border with Russia was the latest to hit China"s mining industry _ the world"s most dangerous. Authorities say safety is improving, but hundreds still die in major accidents each year. The death toll more than doubled overnight, reported the official Xinhua News Agency. A duty officer at Xinxing"s work safety authority and an employee at the company that owns the mine confirmed 87 had died. Ventilation and power were restored in the mine, said the employee, who refused to give his name because he was not authorized to speak to the media. The mine"s director, deputy director and chief engineer were fired Saturday, he said. A total of 528 people were working in the Xinxing (pronounced shin-shing) mine at the time of the 2:30 a.m. explosion Saturday, the State Administration of Work Safety said in a statement. Xinhua reported 420 escaped. Steam was seen Sunday rising from the site of the explosion that resulted from a gas build-up. The blast littered the ground with shards of shattered glass and twisted pieces of metal. A building next to the mine lay crumbled, its blackened roof on the ground. The site was cordoned off by police tape and guarded by a half-dozen officers while a handful of passers-by watched as rescue teams entered the mine shaft. Tang Cunha, a local resident who stood about 30 yards (meters) behind the police tape, likened the destruction caused by the blast to that of a massive earthquake. «I had to come by and see it,» he said. «It"s awful, it"s awful.» Company officials remained hopeful of finding survivors. «If we haven"t found them, to us that means they are still alive,» San Jingguang, a spokesman for the mining company, told reporters. «Rescuing people is still our first priority.»