On August 24, 2020, Administrative Law Judge Sharon D. Calhoun issued a decision denying Respondent’s motion for relief pursuant to Federal Rule of Civil Procedure 60(b) and affirming the underlying one-item serious citation issued by the Occupational Safety and Health Administration. For the following reasons, we set aside the judge’s order and remand for the judge to hold an evidentiary hearing on the issue of the citation’s service. On August 30, 2017, OSHA initiated an inspection of a PetSmart store in Vero Beach, Florida. A week later, Respondent’s safety and compliance manager, Karen Barry, sent OSHA a letter in response to a “Notice of Alleged Safety or Health Hazard” and a request for documents from the compliance officer. In her letter dated September 7, 2017, Barry stated that “[t]o ensure timely future responses” OSHA should “reach out to [her] directly with any questions.” The letter included Barry’s email address, phone number, and fax number. In addition, the letterhead included a mailing address in Phoenix, Arizona. Subsequently, OSHA (through its regional office that conducted the inspection) issued Respondent a citation and sent it via certified mail to the Vero Beach address of the store that had been inspected. The U.S. Postal Service return receipt shows the citation was signed for, but the identity of the individual who signed is unknown.