planemad2,
Sorry if I mis understood what you said, I cannot say at this stage if that was the cause.
This photo gives you an idea of what severe turbulence can do to the vertical stabilizer with delamination not being a factor.
In flight with extensive tail damage - B-52H-170-BW S/N 61-0023 From a famous series of photographs taken after severe turbulence sheared off most of the vertical stabilizer. The aircraft had been specially instrumented for air turbulence research after some operational B-52s were lost. The tail was lost after a severe and sustained burst (+5 seconds) of clear air turbulence violently buffeted the aircraft. The Boeing test crew (Pilot - Chuck Fisher & Copilot - Dick Curry) nursed to aircraft to Blytheville AFB, Arkansas and landed safely. Also note the (inert) AGM-28 Hound Dog missiles still attached to the wing pylons. The dotted line shows the normal outline of the vertical stabilizer and rudder.