Tragic oil plant explosion in Mexico leaves dozens dead, missing

A plume of smoke rises over the State oil company Petroleos Mexicanos' petrochemical plant in Coatzacoalcos, Mexico, Wednesday April 20, 2016. An explosion ripped through a petrochemical plant on the southern coast of the Gulf of Mexico on Wednesday, killing 3 people, injuring dozens and sending flames and a toxin-filled cloud into the air, officials said. (AP Photo/Felix Marquez)

Rosa Villalobos stands in front of army soldiers as she holds up a photo of her son, Luis Alfonso Ruiz, 25, (on the right of the photo), as she tries to get information on his whereabouts outside one of the main entrances to the Pajaritos petrochemical complex in the city of Coatzacoalcos, Mexico, Thursday, April, 21, 2016. Ruiz is one of several workers still unaccounted for while at least 13 people are now confirmed dead and scores of others have been injured in an explosion inside this plant. The state oil company, Petroleos Mexicanos, or Pemex, said explosion occurred in a plant that produces vinyl chloride, a hazardous industrial chemical. (AP Photo/Felix Marquez)

A relative of a missing worker argues with a Mexican army soldier as he demands to be allowed to get more information, outside the Pajaritos petrochemical complex in Coatzacoalcos, Mexico, Thursday, April, 21, 2016. At least 13 people are now confirmed dead and scores of others were injured in a Wednesday afternoon explosion inside the plant. The state oil company Petroleos Mexicanos, or Pemex, said the plant, operated by Mexichem, in partnership with Pemex, produces vinyl chloride, a hazardous industrial chemical. (AP Photo/Felix Marquez)

Mexican army soldiers wearing protective face masks stand guard at an entrance of the Pajaritos petrochemical complex in Coatzacoalcos, Mexico, Thursday, April, 21, 2016. At least 13 people are now confirmed dead and scores of others were injured in a Wednesday afternoon explosion inside the plant. The state oil company Petroleos Mexicanos, or Pemex, said the plant, operated by Mexichem, in partnership with Pemex, produces vinyl chloride, a hazardous industrial chemical. (AP Photo/Felix Marquez)

A security guard protects a store that was damaged by the shock waves of an explosion at a State oil company Petroleos Mexicanos' petrochemical plant in Coatzacoalcos, Mexico, Wednesday April 20, 2016. An explosion ripped through a petrochemical plant on the southern coast of the Gulf of Mexico on Wednesday, killing 3 people, injuring dozens and sending flames and a toxin-filled cloud into the air, officials said. (AP Photo/Felix Marquez)

Relatives of missing workers gather outside the Pajaritos petrochemical complex in Coatzacoalcos, Mexico, Thursday, April, 21, 2016. At least 13 people are now confirmed dead and scores of others were injured in the Wednesday afternoon explosion inside the plant. The state oil company Petroleos Mexicanos, or Pemex, said the plant, operated by Mexichem, in partnership with Pemex, produces vinyl chloride, a hazardous industrial chemical. (AP Photo/Felix Marquez)

BEST QUALITY AVAILABLE - In this video grab a large plume of smoke rises from the Mexican State oil company Petroleos Mexicanos' petrochemical plant after an explosion in Coatzacoalcos, Mexico, Wednesday, April 20, 2016. The explosion killed several people, injuring dozens and sending flames and a toxin-filled cloud into the air, officials said. (Inmel Enoc via AP)

A relative places a list of missing workers outside the local hospital in Coatzacoalcos, Mexico, late Wednesday April 20, 2016. An explosion rocked the nearby petrochemical plant of the state oil company Petroleos Mexicanos ( Pemex ) on Mexico's southern Gulf coast, causing evacuations in the area as a fire billowed a toxin-filled cloud into the air. Officials said three workers died and more than 100 people were injured.(AP Photo/Felix Marquez)

Relatives of missing workers of a nearby petrochemical plant of the state oil company Petroleos Mexicanos ( Pemex ) demand news about their loved ones outside the local hospital in Coatzacoalcos, Mexico, late Wednesday April 20, 2016. An explosion rocked the petrochemical plant on Mexico's southern Gulf coast, causing evacuations in the area as a fire billowed a toxin-filled cloud into the air. Officials said three workers died and more than 100 people were injured.(AP Photo/Felix Marquez)

Relatives of missing workers of a nearby petrochemical plant of the state oil company Petroleos Mexicanos ( Pemex ) pray as they wait for news news about their loved ones outside the local hospital in Coatzacoalcos, Mexico, late Wednesday April 20, 2016. An explosion rocked the petrochemical plant on Mexico's southern Gulf coast, causing evacuations in the area as a fire billowed a toxin-filled cloud into the air. Officials said three workers died and more than 100 people were injured.(AP Photo/Felix Marquez)

Mexican army soldiers wearing protective face masks arrive to bolster security around one of the main entrances outside the Pajaritos petrochemical complex in Coatzacoalcos, Mexico, Thursday, April, 21, 2016. At least 13 people are now confirmed dead and scores of others were injured in the Wednesday afternoon explosion inside the plant. The state oil company Petroleos Mexicanos, or Pemex, said the plant, operated by Mexichem, in partnership with Pemex, produces vinyl chloride, a hazardous industrial chemical. (AP Photo/Felix Marquez)