Seven workers received fatal burns in an explosion and ensuing fire when a heat exchanger violently ruptured after a maintenance restart.

The pressure-containing shell of the heat exchanger burst at its weld seams, expelling a large volume of very hot hydrogen and naphtha, which spontaneously ignited upon contact with the surrounding air.

[5] The lawsuit was settled for $39 million,[1] but as of 2020 the company continued to fight a fine and government accusations that it willfully put its workers in harm's way.

[3] According to the final report released by the CSB, the explosion was caused by high temperature hydrogen attack (HTHA), which severely cracked and weakened carbon steel tubing and led to the rupture.

As a result, the CSB recommended the state adopt more rigorous process safety management attributes and features based on the team's regulatory analysis.