An explosion at a Mexican vinyl petrochemical plant this past Wednesday – April 20, 2016 – has claimed the lives of 24 people and injured over 130 others. Officials also report that 18 people are still unaccounted for. The incident occurred at a plant owned by Pemex, a large Mexican oil company, and jointly operated with Mexichem, a pipe making company.

According to officials, a leak is believed to have caused the blast, which could be felt by nearby residents miles away. Still it is not known what caused the leak. Following the blast, emergency procedures were put in place and communities were evacuated. The explosion did cause toxic chemicals to affect nearby areas.

Pemex has had a documented history of large scale explosions occurring at its facilities, including explosions with multiple deaths and injuries. In 2013, for example, nearly 40 people were killed in a blast at Pemex’ Mexico City headquarters. A 2012 explosion at another facility in northern Mexico also killed close to 30 people.

Wednesday’s blast, which could potentially worsen in regard to casualties involved, calls to question whether proper safety protocol were being following at the facility. Although regulations do exist, they may not be as strict as those in the U.S. Additionally, as we’ve seen in many American plant and refinery explosions, the existence of regulations do not guarantee adherence. Violations and negligence continue to cause death and injuries at these facilities domestically and abroad all the time.