Potentially, whomever was responsible for maintaining that rail could be liable. Even if you don't have an HOA, it is likely the community as a whole, because it is most likely not the case that the rail or bridge is owned by a single property owner. Who owns the bridge and would repair it if it fell down or was damaged--that will help determine who may be liable.If the railing was known to be too weak or risky--which is probably the case, if he was being warned against leaning on it--then it is likely that it was negligent (unreasonably careless) to not replace or repair it so that it was strong enough (PVC is almost certainly an inappropriate railing material); that negligence would give rise to liability. If he was warned, however, he would also have been negligent to at least some degree, and his own culpability should reduce what he could recover in a lawsuit.