My commiserations to the family of the pilot.
I'm not sure I want to comment on the accident directly apart from the fact that it is beyond my comprehension. Notwithstanding that the deck was not NOTAMed as closed, clearly it was obstructed, and marked as closed.
What I would like to comment on is the reported size of the deck on the ST67B - shown as 24ft x 24ft.
The length of the B206L-4 is 42.5ft and its rotor diameter is 37ft; even with the US regulations, which permit a deck to be based upon the Rotor Diameter ('RD') not the 'D', this deck appears to be smaller than the RD of the L4 - smaller than the RD of any version of the B206 (or even the R22).
If the size of the ST67B is as reported, it begs the question why and regulated by who? To discover this is particularly disappointing at a time when the Standard for deck size in ICAO Annex 14 had already been reduced - for helicopters with a MTOM of 3,175 or less - from 1D to 0.83D, and recently mooted that the reduction should be applied to larger types (for example, those in the North Sea).
I would be delighted to hear that this was a typing error; although my sentiments about the systematic reduction in deck sizes still applies.
Mars