On May 12, 1989, Southern Pacific freight train 7551 loses control descending California's Cajon Pass, hitting over 100 mph before derailing into a San Bernardino neighborhood. The crash kills four people and destroys seven homes, and the film traces how a weight miscalculation and a chain of brake failures turned a routine freight run into a disaster. Investigators and archival material lay out the mechanical and human errors behind the derailment, from overloaded cars to warning signs ignored along the descent. Thirteen days later, on the same street, a pipeline damaged by the wreck ruptures and ignites, killing more people in a second catastrophe that investigators link directly back to the original crash. The documentary follows both the immediate wreckage and the slower-burning failure underground, using interviews, photographs, and incident records to reconstruct how oversight lapses at multiple stages allowed one accident to cause another. It is a case study in how a single mechanical failure can cascade through a community over two weeks rather than one night.