Northrop Grumman Corp.’s Pascagoula, Miss., and New Orleans shipyards opened their offices again on Monday as thousands of employees returned to work after the devastation of Hurricane Katrina. Partial ship production was expected to resume on Monday, the company said.

The Los Angeles-based defense contractor said both shipyards have restored sufficient power to resume shipbuilding activities this week. Work began Monday aboard some of the 11 Navy and Coast Guard ships under construction at the company’s Ship Systems unit’s yards.

The largest manufacturing employer in Louisiana and Mississippi, Northrop had a number of shipbuilders report to work last week to help restore the shipyards. The call to all remaining shipbuilders was issued late Sunday. Clean-up and recovery are ongoing.

Partial shipbuilding work had begun at the Pascagoula yard last week aboard two ships, the guided missile destroyer Forrest Sherman and the amphibious transport dock San Antonio, Northrop said in a statement.

Hurricane Katrina significantly damaged some of Northrop’s shipbuilding operations in the Gulf Coast region.