In the latest episode of “energy, explained,” the new podcast from StateImpact Pennsylvania, Megan Holleran tells her family’s story — complete with an unexpected twist — to StateImpact’s Susan Phillips.

The pipeline will carry volatile propane, ethane and butane, which has raised fears of many who live near it — even though explosions are rare. As part of StateImpact Pennsylvania’s “Mariner East 2: At what risk?” series, we put together this video to explain what those substances are and how they act both inside the pipeline and if they got out, and how you should respond if there’s a leak.

Thirteen U.S. airports have runways that could be underwater by mid-century. Airports are working on ways to protect electrical equipment and infrastructure.

“If we find a rare plant and it exists in Pennsylvania and it’s extinct in every other state, then that becomes a valuable piece of information,” a researcher said. Such discoveries could help protect vulnerable species.

The agency agreed to have Sunoco continue construction at eight of 12 locations, where a judge halted work due to public safety and environmental concerns.

Marcellus Shale production is expected to continue, an industry analyst said, and “we’re rapidly approaching a point where you may need to build capacity out of the Marcellus all the way to the Gulf Coast, and that’s an expensive proposition.”