D.C.’s Fire and EMS Chief Gregory Dean is retiring.

Spokesman Doug Buchanan confirmed multiple reports that Dean, who joined the District’s Fire and EMS Department in 2015, would be stepping down. No reason was provided in the decision.

Dean’s arrival came as the department struggled with lagging response times for emergency medical services.

The District has since made progress with the help of a private ambulance company and by directing more non-emergency patients toward rideshares.

Before coming to D.C., Dean had served for a decade as the Fire EMS chief in Seattle.

Multiple sources tell WTOP that Assistant Chief John Donnelly will replace the 70-year-old on an acting basis.