Abstract: At approximately 8:15 pm, on May 26, 2010, worker #1, a licensed plumber, and worker #2, the plumber's future son-in-law assisting with the work, were changing out a pump inside a 12 foot deep by 5 foot diameter well pit at a residence as a favor to the homeowner. The well pit is a brick-lined, hand dug well dating back 100 to 120 years, originally powered by a wooden windmill but adapted to a deep well pump system. The old pump had not been used in 10 to 12 years and was rusted in place inside the well casing. Worker #1 accessed the well pit with an extension ladder and poured up to 3.75 gallons of muriatic acid into the casing to dissolve the rust, exited the pit and waited several hours before entering the pit again to attempt to remove the pump. Worker #1 collapsed due to lack of oxygen or because he was overcome by vapors that had built up inside the well. Worker #2 was working at the top of the well, entered the well to assist Worker #1 and also collapsed. The homeowner called 911. Within minutes a 32 year veteran firefighter arrived in his personal vehicle and became the third victim when he entered the well, attempted to climb back out and then collapsed after falling off the ladder back into the well pit. Shortly after, another Firefighter (6 year veteran) arrived in his personal vehicle and became the fourth victim as he entered the well to assist the victims and also collapsed. Next on scene were 4 more firefighters with Liberty VFD who suited up with self contained breathing apparatus (SCBA), rigged up ropes, and began removal of the victims. During removal of Victim #4, the first out, Muncie Fire Department arrived and assisted with the rescue providing a harness to remove the other victims. Delaware County EMS arrived and transported all victims to Ball Memorial Hospital, where Worker #1 died. Worker #2 was in a medically-induced coma and was found to show no brain activity and taken off of life support on June 8, 2010. Victim #3 received 15 staples to close wounds on his head from falling off the ladder into the well when he attempted to self-rescue and was released from the hospital June 1, 2010. Victim #4 was also placed in a medically-induced coma suffering from respiratory failure and was on a ventilator for approximately 4 days. Victim #4 was released from the hospital expected to make a full recovery. After consulting with Delaware County Health Department and IDEM, Liberty Volunteer Fire Department put 1,800 gallons of water into the well pit to flush it clean and displace any residual acid. It was confirmed through interviews of Worker #1 and Worker #2's family members and employer that Worker #1 was a licensed plumber doing work independently as a favor for a friend. No compensation was to be given for work performed at this residence.