A gas furnace was likely the cause of a "complicated" fire at a Highland Park home on Saturday, according to a firefighter on scene. About 53 firefighters worked 43 minutes to extinguish the fire, located in the 140 block of South Avenue 59. The blaze was first reported shortly before 8 a.m., the Los Angeles Fire Department tweeted. Firefighters initially tweeted than an adult was injured, but Battalion Chief Stacy Taylor later said the home's owner was transported for evaluation and found to be OK.