Two inmates, Richard Matt and David Sweat, escaped from the Clinton Correctional Facility (http://www.businessinsider.com/answers-sought-in-ny-shawshank-redemption-style-prison-escape-2015-6), and to do so they "cut through the steel wall at the back of their cell, crawled down a catwalk, broke through a brick wall, cut their way into and out of a steam pipe, and then sliced through the chain and lock on a manhole cover outside the prison".
The prison officials think it may be (partly) an inside job, maybe they got help from a contractor or someone on the prison staff.
I disagree....I suspect it was mostly an outside
I think someone basically took their time burrowing into the prison from the outside. This would explain a lot, for example, why no one heard anything when the pipes and walls were being cut open.
A steam pipe like the one in the pic is about 1/4" thick, that's some pretty serious stuff to be cutting or breaching even with acid or something like a thermal lance (http://en.wikipedia.org/wiki/Thermal_lance). When I cut 1/8th steel in my shop with a cutoff tool I need eye and ear protection, and it makes one HELL of a noise. There's just no way in the world to keep it quiet.
It also looks like it was cut very cleanly. That doesn't seem like it was done in a couple hours.
So, maybe acid or a oxyacetylene gas cutting torch. Both are pretty quiet overall.
Doing all this from inside without getting caught seems very unlikely. But doing it from the outside
would be much easier. So I think someone likely broke into Clinton to make a path out for these guys.
EDIT: And it looks like I was wrong.
The news sources are saying now that it appears a staff person, Joyce Mitchell
, gave the prisoners access to tools and other equipment used in the escape. Mitchell was an industrial training supervisor in the prison tailor shop where both inmates worked.
It also appears that that Mitchell had agreed to pick up Matt and Sweat in a getaway car, but backed out at the last minute and checked herself into a hospital for panic attacks.
Dang, I really liked my theory, it sounded so good.