The cause of the massive Christmas Eve 2016 sinkhole and sewer collapse in Fraser was a result of "human error," the Macomb County Public Works Commissioner Candice Miller said Wednesday.
According to Miller, while workers were in the Macomb interceptor pipes relining the sewer, they raised a gate too fast causing water to rush out almost like a tsunami.
"They would close the gates...that hold the flow back so that workers could work in the pipes. But when the workers leave the pipe, the operator then has to raise the gate. And you do this following proper protocol -- it calls for the flow to be released over several hours," Miller said. "One time in particular, they released the gate in about seven minutes. So when that happened, they released the flow here in seven minutes instead of several hours, you had a tsunami, a water hammer hit the wall and it was like a bomb went off."
The 11-foot sewer main collapsed underground leading to the giant sinkhole.
City officials are currently conducting an engineer evaluation to determine how much the recovery will cost. Eleven communities were affected by the sinkhole.
"We'll look at all the numbers, and we'll see what happens. But again if I'm the insurance company, there's little doubt of what actually happened here," Miller said.
Watch the press conference below: