I would not say a lawsuit is in order - but I would definately say signs should be posted for sure. It surprises me how cavelier people can be. It is slippery there, with shall crumbling beneath your feet.
Last summer I was hiking there (though not to the bowl) and i saw a family - parents and two young children. The children and dog scamperred ahead up towards the bowl. I tried, best I could without interfering to point out the conditions. First I asked if they had been there before. They smiled and said they were just driving by - they were tourists. Then I said - eveyrone feels differently about the risks here, but you should know someone falls every year and it can get pretty slippery.
They didn't seem too concerned - which certainly was their peroggative. I wasn't sure if i over stepped boundaries by advising strangers - and we should each decide for ourselves how to live. BUt I was bothered they didn't really grasp that this was serious bussiness. Especially with their kids so far out of sight, the parents weren't their to determine if the path was safe to walk on or not.
None the less, to be fair, I do think it would be appropriate to post signs "Enjoy yourself, but be very aware paths are slippery and at least one person falls to their death every year"