A woman based in western Pennsylvania was among the 239 people aboard a Malaysia Airlines jet that disappeared en route to Beijing over the weekend.

Mei Ling Chng, a senior process engineer for Flexsys America in Monongahela, near Pittsburgh, "is confirmed to have been on the flight," a company spokeswoman said.

Tracy Kilgore, of Flexsys parent firm Eastman Chemical Co., which is based in Kingsport, Tenn., told reporters in an email that officials "are deeply shocked and saddened."

Chng went to work for the chemical company Solutia in Malaysia in 2005 and transferred to Monongahela in 2010, Kilgore said.

She said Chng was "remembered fondly by her co-workers as being... pleasant and happy as well as well-respected."

Flexsys makes and supplies chemicals for the rubber industry.