This news is from Mexico. There is an explosion. It happens at a petrochemical plant. Three people die. The explosion injures more than 100 people.
Pemex is a Mexican national oil company. Pemex owns the plant. This is not the first explosion. The company does not know the cause of the explosion.
The plant makes a chemical. People use it to make PVC pipes. This chemical is dangerous.
The explosion sends up a cloud. It is full of chemicals. People are not safe. They must stay inside.
Difficult words: petrochemical plant (a building where people make things from petroleum or natural gas), cause (a reason, why something happened), PVC (polyvinyl chloride; a chemical), pipe (a long, narrow thing with space in it; things such as water can move in a pipe).