A heavy equipment operator at a Wisconsin mine died when a pump raft he was working on in a stormwater retention pond capsized causing him to drown. Federal investigators said a lack of training and misuse of equipment led to the fatality.
Investigators with the Mine Safety and Health Administration (MSHA) found that the incident occurred because the mine operator:
- didn’t provide safe access for miners to repair the pump and pump raft equipment
- failed to properly train miners on safe work procedures and how to properly work on pump raft equipment, and
- used pump rafts beyond the manufacturer’s stated capacity by allowing miners to use the rafts as work platforms while performing maintenance and repairs.
Donned life jackets, used boat to get to rafts
Tony Killian was a heavy equipment operator at the AMI Silica LLC mine, a surface sand mine, in Jackson County, Wisconsin.
On March 22, 2022, Killian and a co-worker were assigned to replace discharge pipes on pumps in several stormwater retention ponds around the mine. They had been assigned to do this the previous day, but were unable to complete the task because of a buildup of ice on the retention ponds.
The retention ponds ranged in depth from 8 to 11 feet and each was about 145 feet wide, and 180 feet long.
When Killian and his co-worker found the ice had melted sufficiently for them to access the rafts the pumps were installed on, they donned life jackets and took a 14-foot rowboat out to the first raft.
Pump rafts used four plastic floats mounted to steel frame
The pump rafts were Turbi-Float Floating Pump Systems that consisted of a:
- 60-horsepower motor
- 500-gallon-per-minute pump
- steel frame, and
- four plastic floats that were each 2-feet wide, 2-feet tall and 4-feet long.
The floats were connected to the steel frame of the raft by four 4.7-inch-long bolts that passed through the frame and the slot in the top flange of the float.
Raft capsizes, causes boat to sink
At the first pump raft, the two workers climbed out of the boat onto the raft and successfully replaced the pump’s discharge pipe.
When they got to the second pump raft, they once again climbed out of the boat and unto the raft, which had been in this pond since 2017. Killian was standing on one of the plastic floats as he began to install a discharge line, and the float detached, causing Killian and his co-worker to fall into the pond.
As the co-worker surfaced, he couldn’t see Killian and began searching for him. The co-worker couldn’t locate Killian and had to swim to shore since the capsizing of the raft caused water to fill the boat they’d been using.
Emergency responders find worker entangled in raft
Meanwhile, Killian’s supervisor stopped heavy equipment operation due to the start of rainfall. The supervisor and two other miners drove out to check on Killian and his co-worker to see if they should stop work because of the rain.
As they drove toward the first pond, Killian’s co-worker stopped them and told them what happened. They called 9-1-1, donned life jackets and swam out to the pump raft to search for Killian, but couldn’t find him.
Emergency responders arrived a few minutes later and used a telehandler, boat and tow straps to get the capsized pump raft to shore. Killian was found entangled in the raft. He was pronounced dead on the scene.
Ice had caused cracks in plastic floats
MSHA investigators found that:
- the raft’s plastic floats had cracked in several places from pressure exerted on them by ice because it was left in the frozen water of the pond each winter since 2017
- the pump raft had warning labels stating, “WARNING: This float system is designed to support only specific matching models of pumps … and should not be used as a platform for any other purpose”
- Killian’s weight placed on the plastic float caused the cracks to break through and capsize the raft
- the mine operator knew the safe way to perform maintenance and repairs on the pump rafts was by bringing them to shore but it allowed its workers to access them by boat anyway, and
- Killian and his co-worker hadn’t been trained how to properly perform maintenance and repairs to the pumps and pump rafts.
Mine operator now has written safety procedures for this task
MSHA found that the root causes of the incident were that the mine operator:
- didn’t provide safe access for miners to repair equipment on the pump raft
- failed to properly train miners assigned to work on pump raft equipment on safe work procedures, and
- used the pump raft beyond the designed capacity intended by the manufacturer by allowing miners on the raft while performing maintenance and repairs.
The mine operator has since developed new written procedures requiring workers to remove pump rafts from the water before performing maintenance and trained them on this procedure. It also updated its task training plan to include training on pump raft and pump equipment maintenance and repair.
