The recent, dramatic decline in oil and natural gas prices has forced Radnor’s Penn Virginia Corp., one of the region’s oldest surviving business, to file for bankruptcy protection, writes Andrew Maykuth of the Philadelphia Inquirer.

Penn Virginia Corp. was founded in 1882 by Philadelphia coal barons, and had transitioned to shale-oil production in recent years. However, the plummeting of oil prices has diminished the value of the company’s oil and gas reserves.

According to Maykuth, Penn Virginia’s acreage is concentrated in Texas but includes holdings in Pennsylvania’s Marcellus Shale region. The company listed assets of $518 million and debts of $1.4 billion in filings with the U.S. Bankruptcy Court for the Eastern District of Virginia.

“We believe using the Chapter 11 process is the most efficient way to achieve our financial objectives and deleverage the company’s balance sheet,” Edward B. Cloues II, chairman and interim chief executive, said in a statement.

Penn Virginia joins the ranks of 69 oil and gas companies nationwide that have filed for bankruptcy since the beginning of 2015, according to Haynes & Boone, a Houston law firm that publishes the Oil Patch Bankruptcy Monitor.

The number of drill rigs operating in the Marcellus Shale region has plummeted from 115 five years ago to 16 this month, writes Maykuth. While it maintains a small number of operating gas wells in the state, Penn Virginia halted new drilling in the Marcellus several years ago to concentrate on the oil-rich Eagle Ford formation in South Texas.

Click here to read more about Penn Virginia’s bankruptcy filing in the Philadelphia Inquirer.