The Operations Book for 933 squadron is available to download free from the National Archives,
ref Air27/2272/5. Around 10 am there were 36 balloons operating in 2 Flights in Gosport, commanded from 12 Balloon Centre, Portsmouth.
The event is reported very briefly on page 330:
"Gosport 12/8/40
1554 From B.Flight. - 33/9 Balloon breakaway between 1200 and 1300 hours. Actual time unknown No witnesses Winch burnt out Cause Bomber shrapnel"
However on the previous page, at 1158 there had been a red air-raid warning from Portsmouth, then
"1305 From F/Lt Kelly R.A.F. Reporting a direct hit on 33/9 Evacuation in progress 2 bodies recovered No. of other casualties unknown."
[a message to 12 Balloon Centre]
"1350 To 12 BC - 33/9 direct hit. 33/7 both sides hut caving in. Hut habitable but needs repairing."
(Amended)