Firefighters are battling one of the Big Island's largest fires in recent years.

In two days, a fire in the mountains above Pahala scorched about 400 acres, while a second larger fire closer to the sea burned nearly 4,000 acres.

That large fire tore through old plantation land, where a thriving agricultural industry has grown.

"Four thousand acres -- that's a considerable fire -- the biggest of the season so far," said Deputy Chief Glen Honda, with the Hawaii Co. Fire Department.

The flames swept through farms that grow macadamia nuts and coffee.

"Seven of the coffee farms had a lot of damage. The fire burned up the ground around the trees and caught some of the trees on fire, damaging the crops," said Gloria Camba, with the Ka'u Coffee Farmers Cooperative.

While crops were damaged, the flames missed the Ka'u Hospital, but not by much.

"It was really frightening the way the fire came up much closer to the hospital than we realized," said hospital administrator Merilyn Harris.

There was no fire damage, but soot from smoke covered the inside of the hospital. Even in a safe room filled with air conditioners, filters and air scrubbers -- normally used on very voggy days -- the smoke was so bad, patients had to be evacuated.

Crews cleaned up the hospital and were able to reopen the emergency room Tuesday evening. On Wednesday, the 15 evacuated long-term-care patients are expected to be able to return as well.

"They want to come home soon and we sure want them to come home," said Harris.