All of the cited accidents would be impossible if people had taken the 4 seconds required to remove the security key. It's tragic that children died, but entirely preventable.
There's a reason every treadmill on the planet that you can purchase has on the very first page of the manual that you need to keep children and animals away from it while it's in use, and to remove the security key when it's not in use.
I challenge those of you downvoting away to show me how this accident would have occurred if the parent(s) in question had removed the safety key.
I also challenge you to find me a treadmill that wouldn't react in the exact same fashion if you jammed an exercise ball into the back of it. Here's a hint: none of them stop. The force of you striking the treadmill while running is greater than the resistance of a treadmill pulling on that ball. I expected better than twitter reactionism out of HN.
And for reference: https://www.youtube.com/watch?v=eNlX4VaN2bU
https://www.kidspot.com.au/parenting/real-life/in-the-news/t...