A powerful explosion at a petrochemical facility in Mexico killed at least three people and injured dozens of others Wednesday. The blast sent clouds of toxic fumes into the sky at national oil company Pemex in the Gulf state of Veracruz. The explosion occurred at the company’s chlorinate-3 plant near the port of Coatzacoalcos, a major oil export hub. Luis Felipe Puente, head of federal emergency services, said 105 people were hospitalized, including 58 Pemex workers. It’s unclear what caused the blast, but the company warned local residents to stay away from the facility.