Here is where things separated. It looks like the rubber boot has separated, but the tube itself is probably OK. The storm is still on, so I'm going to wait to do a more careful check.
The SteppIR is one of the original 3-element type. It went up in 2004 IIRC, and has been trouble-free until now. I'm not complaining. We will probably have to bring it all down and replace the silicone rubber bits.