General Dynamics NASSCO said it plans to lay off part of its workforce because of a flooding incident in a dry dock in mid-July.

The General Dynamics (NYSE: GD) unit plans to lay off as many as 1,493 employees by Sept. 26, according to a notice filed with the state.

A ship under construction — a 784-foot expeditionary warfare support ship that will take the name USNS Miguel Keith — was in the dry dock, called a graving dock. A barrier that kept seawater out of the facility collapsed, said a representative of the San Diego Fire Department, which was called to the scene after the incident on July 11.

There were no injuries in the incident, NASSCO reported.

The California Employment Development Department said it received a notice that NASSCO would conduct layoffs on Aug. 3. It was unclear whether NASSCO would lay off all 1,493 employees.

The July incident made an impact on NASSCO’s business plans. The company had been on a hiring push.

“We are working diligently so not all employees who were notified will be affected,” NASSCO said in a statement. “We regret the impact this will have on employees and their families. The company has arranged a variety of programs and resources to assist those who will be affected.”

San Diego’s shipbuilding and repair business tends to experience booms and busts, depending on the availability of U.S. Navy contracts. NASSCO also does commercial work when it becomes available.