[ 1:08 PM EST — Just hours after this post was first published Thursday morning a train carrying both crude oil and propane gas derailed in western Pennsylvania. The extent of the damage was not yet clear.]

A gas pipeline explosion in Kentucky early Thursday that sent at least two people to the hospital, destroyed three homes, two barns, numerous cars, and left a 60-foot crater in the ground is the fourth significant fossil fuel-related disaster in the U.S. in as many days.

“The latest string of disasters bolds and italicizes a basic fact: fossil fuels aren’t safe. Not for our communities, not for our environment, and certainly not for our climate.” —Jamie Henn, 350.org

According to media reports, the cause of the explosion and subsequent fires in the town of Knifley, Kentucky, about 90 miles south of Louisville, was not known but one witness said the blast lit up the sky “just as plain as day.” The section of the pipeline that exploded has been sealed off and an investigation is underway, authorities said.