Randolph Mantooth died Thursday at a hospice facility in Ventura, California at the age of 80 after battling multiple cancers over several years.
His brother Donald confirmed the death. He is survived by his wife Kristen and his siblings.
Mantooth played firefighter-paramedic Johnny Gage on NBC's Emergency! from 1972 to 1977, a role that did something television rarely accomplishes, it changed the world.
When Emergency! debuted in January 1972, there were only 13 paramedics in all of California. Nobody knew what a paramedic was.
The show, created by Dragnet legend Jack Webb, followed Squad 51 and the LAFD in a near-documentary style that made the profession visible to the entire country.
By the time it ended in 1977, paramedic programs had been established across the United States. Generations of paramedics and EMTs cited the show as the reason they went into the field.
Mantooth performed most of his own stunts alongside co-star Kevin Tighe, who played his partner Roy DeSoto.
He had a personal stake in what the show represented, in the 1970s he was saved by paramedics who recognized carbon monoxide poisoning from a faulty furnace, and in the 1980s emergency personnel revived his sister after a car accident.
"Do I respect paramedics? Do I respect firefighters?" he said in a Television Academy interview. "There's a debt I owe them that I probably can't ever pay back. But I'm gonna try."
After Emergency! he appeared on dozens of shows including Dallas, Charlie's Angels and Criminal Minds and spent nearly two decades in daytime soap operas.
In 2012 the Los Angeles Fire Department named him and Tighe Honorary Fire Chiefs. He was 80 years old and spent his life paying that debt back.