Construction of two nuclear reactors in South Carolina was halted Monday after the project’s owners announced they were suspending work on the multibillion-dollar power plants.

The reactors, which were supposed to be operational by 2019, were among the first American nuclear power projects to be built in decades.

A Westinghouse analysis showed that the station wouldn’t be finished until 2024, according to one of the utilities, Santee Cooper.

“The best case scenario shows this project would be several years late and 75 percent more than originally planned,” Santee Cooper President and CEO Lonnie Carter said in a statement. “We simply cannot ask our customers to pay for a project that has become uneconomical.”

Duke Energy has the authority to seek recovery of tens of millions of dollars from South Carolina customers for money it has already spent on a proposed nuclear plant near Gaffney, whether or not the plant is ever built.

The authority rests under the same 2007 state law that has left South Carolina Electric and Gas ratepayers to foot the bill for the failed VC Summer Nuclear Station near Jenkinsville north of Columbia.

Duke is working with the same bankrupt company that was building the VC Summer reactors.

That would put Duke’s South Carolina ratepayers on the hook for $58 million to $69.6 million in costs sunk into the project thus far.