By Elizabeth Daley

PITTSBURGH (Reuters) - A councilwoman who died earlier this month easily defeated the only other candidate on the ballot for the Pennsylvania county that includes Pittsburgh, results showed on Wednesday.

Incumbent Barbara Daly Danko, 61, died of cancer on May 6 but remained on Tuesday's ballot for the party's nomination for a seat on the Allegheny County Council.

She defeated her opponent, Caroline Mitchell, 5,575 to 4,015. There were no Republican candidates vying for the seat, one of 15 representing Pittsburgh and the surrounding suburbs.

Mitchell, a retired chemical engineer and lawyer could not be reached for comment.

"It was a sympathy vote for Daly Danko," said Nancy Mills, chair of the Allegheny County Democratic Committee, which endorsed Daly Danko.

The incumbent was an outspoken opponent of hydraulic fracturing, or fracking, in county parks. Backers of the controversial technique for extracting oil and gas recently won a legislative battle to allow the practice. Environmentalists say fracking can contaminate ground water and trigger earthquakes.

"Clearly she was well-respected by her constituents, which is pretty much as good as it gets for an elected official," said Jared Barker, the county council's chief clerk and director of legislative services.

The county council is expected to appoint someone in the next month to fill Daly Danko's seat until November, Barker said. At that time, voters will pick someone to fill the remainder of her term, which ends in January.

By Aug. 15, Democratic officials in Daly Danko's district will select a replacement to appear on the November ballot, Mills said.

Pittsburgh, the second-largest city in Pennsylvania with a population of about 305,000, is the seat of Allegheny County.

(Reporting By Frank McGurty; Editing by Alan Crosby)