It's been four years since a deadly explosion at an oil refinery shook the town of Anacortes, Washington. The question of who's responsible for seven workers' deaths still hasn't been answered fully. Refinery owner Tesoro agreed to pay millions to families of the dead, but the company is fighting accusations that it willfully put its workers in harm’s way. With multiple legal proceedings continuing to swirl around the accident, it remains unclear whether anyone will be held accountable for the human cost of Tesoro gasoline. John Ryan brings us part one of this KUOW investigation.