Groton — A local manufacturing plant has laid off 71 employees due to the coronavirus pandemic's effect on its business.

PCC Structurals, which makes parts for the aerospace and energy industries and whose customers include the Department of Defense, notified the state this week that it expected the layoffs, some of which occurred April 10, to be fully implemented by Wednesday.

About 170 employees remain at the plant at 839 Poquonnock Road, which is operating, according to a spokesman at PCC Structurals' corporate headquarters in Portland, Ore.

"As the impact of the pandemic and other macroeconomic factors have weighed on the nation, many of our customers have or intend to curtail or reduce their production," David Dugan, director of corporate communications for Precision Castparts Corp., wrote in an email. "Due to the resulting impact on orders, we have reduced our workforce to align our production with our customers' needs."

PCC Structurals is a division of Precision Castparts.

Dugan wrote that the company was working with the state Department of Labor to assist the laid-off workers.

In a letter filed in accordance with the federal Worker Adjustment and Retraining Notification Act, commonly known as WARN, PCC Structurals' general manager, Mark Slaughenhoupt, wrote that the company was unable to provide more notice of this week's layoffs because "circumstances were not reasonably foreseeable until recently when the full impact of COVID-19 became clear."

At the time of the first "separation" earlier this month, "we felt we had reduced our staff to acceptable numbers, and we were well below the WARN threshold," he wrote. "Due to continued (downturn) in our business, we are forced to reduce our workforce further and while the Company does not believe that it will exit enough employees to reach the WARN threshold, out of an abundance of caution, the Company provides this notice."

All 71 affected employees were to be notified that "their separation from employment" is permanent, Slaughenhoupt said in the letter. Attempts to reach him Thursday were unsuccessful.

The WARN Act requires employers with 100 or more full-time employees to give 60 days' notice of a plant closing or mass layoff if it includes a workforce reduction of at least 33% or the laying off of at least 500 workers at a single employment site.

PCC Structurals workers in more than two-dozen job categories lost their jobs, including finisher, grinder, process engineer, robotic operator, machinist and operations supervisor.

Groton Town Mayor Patrice Granatosky said town staff had reached out to the employees and would provide them with whatever assistance they could.

"This is certainly a loss, especially for the workers because of the employment situation," she said. "It will be difficult for them to move into other jobs."

Precision Castparts also reduced its workforce in Oregon, where it's one of that state's largest manufacturers. The company is owned by Berkshire Hathaway, Warren Buffett's investment firm.

b.hallenbeck@theday.com