Kentucky –

“…the issue reached a tipping point after the July 7 incident at Oxford Circle Apartments off Versailles Road. 62-year-old Samuel Gross died, and 11 others were hospitalized after high levels of carbon monoxide were found inside the apartment complex…current rules state that any buildings constructed after 2011 are required to have carbon monoxide detectors if they have gas utilities or an attached garage. However, many older buildings in Fayette County are not required to have them.”

https://fox56news.com/news/local/lexington/lexington-council-moves-forward-on-carbon-monoxide-detector-requirement-after-deadly-leak/