Former workers at what was once one of southwestern Connecticut's biggest employers are now suing their old company over health insurance.

Retired workers at the Stratford Army Engine Plant say their former employer is breaking a promise to pay their medical bills for life.

The plant, which made parts for helicopters and large tanks, shut down almost 20 years ago.

At the time, its unionized workers were promised, in writing, lifetime medical coverage for them and their spouses.

Honeywell International sent those workers a letter saying it is discontinuing those benefits at the end of this year. As a result, five workers are now suing Honeywell for breach of contract.

In a statement, the company said, "Honeywell periodically evaluates how we deliver the most affordable health care coverage...Obamacare...has provided more options for Americans to purchase affordable...health insurance. As a result, Honeywell intends to terminate medical and prescription drug coverage."

The move comes after a Supreme Court decision last year questioning whether companies must honor promises of lifetime medical coverage.