Wouldn't be the first time this has happened to Cherry Run. For a while during the 70's and 80's, it was a regular event. As I recall, the only time it actually led to a significant fish kill was when some yoyo working for one of the many oil supply or drilling ops in the area at the time stopped at the bridge in Plummer (about halfway up the watershed) and emptied whatever was in his truck into the creek. I can't remember what he was carrying, maybe gasoline or some solvent. That did a number on the creek.
If the actual spill amount was in the 25 gal. range, this is no more than probably a hundred (he**.., several hundred now that I think about it..) other like episodes spilled through the PA oil region in the last 40 or so years. They've been pretty common.
One saving grace with these spills is that with the usual stream gradient/volume in the region and with the usual small size of the spill, very little mixing occurs and damage is usually pretty negligible. Usually.
But, in any event, in these days when, due to sky high crude prices, the industry in PA is probably chomping at the bit to crank things up, this is just one more reason to make sure they are on a short leash in regulatory terms..