PORT NECHES, Texas – PORT NECHES, Texas – 6 p.m. Update:A class-action lawsuit was filed against the Texas Petrochemicals Group (TPC) on behalf of the residents of Port Neches whose property was damaged as a result of multiple explosions at a chemical plant in Port Neches. 3:30 p.m. Update:Jefferson County Judge Jeff Branick issued a mandatory evacuation at about 3:30 p.m. for people within a 4-mile radius of the TPC group plant. What is Butadiene, the chemical burning at the Port Neches plant explosion? Original story:Another explosion has occurred at a plant that produces chemical and petroleum-based products in Port Neches, Texas. TPC Group sincerely remains focused on protecting the safety of responders and the public and minimizing any impact to the environment.