Abstract: At 12:30 p.m. on June 7, 2021, an employee entered a sewer manhole to estimate the amount of materials needed to perform a manhole repair when the employee was overcome by high levels of hydrogen sulfide at the base of the manhole shortly after entry. The employee did not perform atmospheric monitoring and had not donned his harness with rescue tripod before entry into the confined space. A four gas monitor and rescue equipment were located in the employee's work vehicle. Coworker #1 (attendant) and Coworker #2 (helper) were not trained or equipped for performing a confined space entry rescue. A volunteer fire department responded within 8 minutes and performed the confined space entry rescue shortly after arrival. The employee was killed by overexposure to hydrogen sulfide.