The death toll from Friday's oil pipeline blast in the coastal city of Qingdao in east China's Shandong Province has risen to 55 with nine people still missing and 136 hospitalized, state-run Xinhua News Agency reported Monday. The accident happened in Huangdao District after oil leaked from the petroleum pipeline owned by Sinopec, the country's largest oil refiner. The pipeline, which has been in use for 27 years, measures 711 mm in diameter and runs about 250 km, with an annual oil transfer capacity of 10 million tons, according to Xinhua. On Sunday, Chinese President Xi Jinping ordered a large-scale production safety check and warned various industries to learn the lesson after the fatal explosions from a leaking pipeline, as he inspected the rescue work and heard reports on the management of the accident. "This accident once again sounded an alarm for us that production safety must be ensured without loosening hold. Otherwise, it will bring irredeemable loss for the country and the people," Xi said, urging various industries to improve safety supervision and preventive measures. Xi also urged all companies to pay adequate attention to safety investments, safety training, grassroots management and emergency rescue and relief under the strict supervision from governments at all levels. Sinopec's board chairman Fu Chengyu made an apology on Saturday over the explosion and vowed to find out the cause. According to a statement posted on the company's official microblog, Fu said Sinopec will conduct rescue work at all costs and cooperate with the investigation team dispatched by the State Council to find out the cause of the accident.