Sunoco will close down its oil refinery in Delaware County over the next three months.

Sunoco had planned to power down the facility in July. But company officials say the market has changed, demand for oil is weak and it will have to shut the plant down right away.

The Sungate diner next to the Sunoco refinery in Marcus Hook has a sign in the window that says, "We support our oil workers."

Sean Brechemin, who was having lunch at the diner Friday, is a union steamfitter who does work in the refinery. He said the closing will be felt all over this corner of Delaware County.

"I've been to many rallies trying to keep these plants open. And they're important. They're important to the community they're important to the state," said Brechemin.

Sunoco will keep about 100 people on--and has started laying off about 400 others.

Pat Lee, who said she knows a lot of people who work at the refinery, lives right down the road and watches trucks travel in and out every day.

"The refinery has done so much for this area and to do something like this is a disgrace," she said.

Many residents and workers who didn't want to comment "on the record" questioned why the company would close the plant just before Christmas.

Sunoco's announcement comes on the heels of a decision to idle the ConocoPhillips refinery down the road. Both companies have put their plants up for sale.

A Sunoco spokesman said the company has lost $800 million on its Marcus Hook facility since 2009. The company's smaller refinery in Philadelphia will be closed in July.

"Decisions like this aren't made lightly," said Sunoco spokesman Thomas Golembeski. "They impact real people. And we'll work closely with communities as this idling process takes place."