A contractor working at the former Sunoco refinery in Delaware County was killed Monday afternoon in an industrial accident, officials said.

The accident, specifics of which are not yet known, occured around 2:15 p.m. on the grounds of the Marcus Hook Industrial Complex, according to a Sunoco Logistics news release.

In the release, the company said it was "saddened" by the news.

"No words can express the sorrow and pain that come when such a tragic event happens," according to the news release. "Our deepest sympathies go out to the family and friends of the individual who died. They have suffered a devastating loss."

Joe McGinn, a Sunoco Logistics spokesman, said the incident is still under investigation.

The former refinery is being converted to a terminal to receive and ship natural gas liquids such as propane from the Marcellus Shale region.

Editor's Note: This story was revised to correct that the Sunoco facility is no longer a refinery, but is being converted into a natural gas terminal.