A fire that burned through a Medford home belonging to the son of Senator Elizabeth Warren was likely caused by oily rags, according to officials. Following an investigation involving the Medford fire and police departments as well as Massachusetts State Police and the State Fire Marshal’s office, authorities said the Tuesday morning fire was accidental in nature and “most likely caused by the combustion of oily rags that had been used in ongoing renovations.” Firefighters responded to the home on Terrace Road around 1 a.m. where crews had to deal with both water pressure challenges as well as issues created by the home’s elevation. No injuries were reported after the fire was put out, with authorities noting at the time that the home belonging to Alexander Warren had been under construction and vacant.