The remains of a third victim have been retrieved from the wreckage of a Bronx fire, as the District Attorney’s Office moves to rule the blaze a homicide with a person of interest being sought, according to sources and reports. FDNY fire marshals pulled the body from the mixed-use building Saturday, according to News 12 . The charred out husk of the Third Avenue Mott Haven building where a fire in a deli resulted in the deaths of three people. Tomas E Gaston for NY Post The mixed-use building went up in flames at 5 a.m. on Wednesday. The cause of the blaze has yet to be determined. The Bronx District Attorney’s Office is considering classifying the fire a homicide, sources told The Post. A person of interest is currently being sought but has not been identified by authorities, sources said. A second victim was found on Thursday and the first victim, identified only as a male, was pulled from the ashes shortly after the fire was brought under control by the FDNY, according to News 12.…