blue canary
n.— «Col. Rich Greenwood, UHP deputy director, said the troopers who arrive at an accident first are usually the ones in the most danger. He said the program will prevent those first-responding officers from becoming victims. “Officers will no longer be a blue canary.”» —“Software shields UDOT from hazards” by Pat Reavy Deseret News (Salt Lake City, Utah) Oct. 5, 2000. (source: Double-Tongued Dictionary)