"In the five years before a massive leak of toxic gas killed four workers at DuPont's La Porte property, four plant managers had come and gone.

DuPont had spun off or sold a series of processing operations that had shared the sprawling plant for decades.

Employment had plunged.

Through all the turmoil, the pesticide unit where the four died remained one of the plant's cash cows, former employees say. But only weeks before the Nov. 15 disaster, that unit's longtime boss had taken over as manager of the entire plant, leaving his job vacant. And many other seasoned operators who best knew how to troubleshoot the pollution-plagued unit's maze of poorly labeled pipes and tanks had retired or transferred out - leaving behind mostly rookies."

Mark Collette and Lise Olsen report for the Houston Chronicle February 20, 2015. [2]