It all depends on the state, the installation (perm or traveling) of the ride, who owns the ride, and the laws governing that jurisdiction as to whether what happened is a criminal act or not.
I really don't think anyone needs to worry that another child will ever go on this same water ride--it will very likely be shut down altogether or changed into some other kind of ride (a safer ride). And all of that will take a few years as the civil lawsuits work their way through the system. In the meantime this ride will very likely stay closed because of there being a death. I mean on top of all that, can you really imagine any loving parent allowing their kid to ride this, knowing what happened? I highly doubt you'd see many younger kids being allowed to get near the thing.
If you're truly worried, then look at other parks and other rides that are not closed down, join together with other parents, and advocate for safe and properly inspected & regulated rides. Don't leave it up to the government, take action. This ride, however, is done, at least for a significant period of time.