The recent Tianjin tragedy has uncovered major flaws in the work safety sector, the Chinese president said.

In a press release Saturday, Chinese President Xi Jinping urged the government to learn from Tianjin hard lesson to avoid any future disasters.

He called on the government to improve emergency services and tighten monitoring on safety rules in workplaces across the country.

On Thursday, China’s president promised a “thorough investigation” after huge explosions ripped through chemicals warehouses in the port city of Tianjin, killing at least 50 people and disrupting operations at one of the world’s busiest ports.

The explosions, which sent a mushroom cloud over the city, occurred late on Wednesday, half an hour after emergency services responded to a fire at warehouses belonging to the Ruihai International Logistics company. Several firefighters were among the dead.