It's grossly simplistic to assume that a single person is somehow responsible for deliberately designing a known-to-be deficient system. Hindsight is always 20:

It's grossly simplistic to assume that a single person is somehow responsible for deliberately designing a known-to-be deficient system. Hindsight is always 20:20 and safety is one of those things that improves over time as accidents occur and measures are taken to prevent their reoccurance. Just think of how many safety features a modern car has: were 1980's cars criminally unsafe - no, they simply hadn't yet incorporated lessons yet to be learnt and technologies yet to be invented. There's a huge grey area too, as workers often ignore safety rules or bypass them to save time. An accident with a machine might be due to a worker failing to operate it correctly or to double-check that some mechanism is correctly engaged. It might be the fault of a mechanic who has incorrectly maintained the machine. It might be a flaw in the design of the machine, which could not be foreseen. It might be a fault with the machine due to a supplier, e.g. inferior bolts. It might be the fault of a fellow worker, who forgot to perform a safety check - should we throw them in jail? Whatever the case, the employer should compensate the worker - and do so justly - but the issue of the employer's criminal responsibility is complex indeed. From a legal standpoint it's vital to distinguish between someone who unwittingly designs something unsafe, having followed reasonable and standard practice versus someone who is negligent and actively ignores the safety of others. Criminal negligence exists and is prosecuted, but it's important to realise that accidents can and do happen.