Abstract: At 11:45 a.m. on February 23, 2023, an employee working for a city water department was repairing a leaking 12-inch PVC waterline main valve. The valve was located in a utility vault approximately 5 feet deep. The employee turned off the water to the west of the valve by opening multiple fire hydrants. He and a coworker then closed the valve stopping the water from flowing. The employee did not turn the water off on the East side. The repair work involved repairing or replacing a gasket on the west side of the valve. The employee attempted to tighten the flange hoping that the gasket would not need replacement. The bolts on the flange were corroded and he was unable to remove the lower bolts due to water and sludge in the vault. The employee exited the vault and waited for the vacuum truck to clean out the vault. The employee entered the vault and attempted to remove the bolts but did not succeed. He decided to cut the pipe with a hydraulically powered concrete cutting saw. While cutting the waterline, the concrete saw jammed and water flowed into the vault. The employee caught his hand inside the pipe under the valve trapping him in the vault. Water flowed out the top of the vault and into a nearby water retention area. A coworker who was acting as the attendant outside the vault flagged down a police car and asked them to call 911. The coworker left to shut off the water main two blocks away. The fire department arrived within minutes and tried to assess the situation which was hindered since the coworker left. They pulled on a rope in the vault hoping it was an employee, but just pulled a pump out. They then saw a boot floating in the water and attempted to pull the legs out with no success. They secured the legs with a rope secured to a backhoe and worked for approximately 47 minutes to free the employee. At 12:37 pm, they removed the employee from the vault and transported him to a local level one trauma center, where he was pronounced dead from drowning.