MIAMI—Michele Gillen, a former South Florida television investigative reporter, has died. She was 66. Longtime friend and producer Marcia Izaguirre confirmed Gillen’s death from natural causes in a Facebook post Friday. “For all those who knew her, she was a relentless warrior who fought indefatigably for the vulnerable,” Izaguirre wrote. “In every story she delved into, she aimed to discover the truth and spur change to improve the quality of life of her community.” Gillen won 39 local Emmys over several decades. Gillen graduated from Emerson College in Boston in 1977 and took a job at a TV station in Bangor, Maine, a short time later. She moved to Miami in 1980 to work for WPLG-ABC10, where Izaguirre said Gillen’s work on housing facilities for the elderly led to national legislation against elder abuse. Gillen moved to NBC in 1988 as a correspondent for the national news program, “Dateline.” Gillen …