Explosion Causes Massive Fire At Electrical Substation in Dallas Dallas Fire-Rescue crews responded to a reported structure fire at an Oncor electrical substation along Sargent Rd early Sunday morning. Units were dispatched to the scene at approximately 1:00am. Upon arrival, firefighters found heavy smoke and high flames coming from the substation. Crews requested Oncor be notified to immediately shut down the power. Once power was shut off, firefighters began fire attack to bring the fire under