Yes, it is most likely a crime. Tying and gagging someone against their will is a form of restraint and can be considered assault or false imprisonment. In a public setting, it also causes public alarm and distress. Laws are in place to protect individuals from such non - consensual and violent acts.
If it's safe to do so, you can try to untie her gently while waiting for the police. But make sure not to destroy any evidence that might be on the ropes or gag. You can also talk to her softly to keep her calm.
Perhaps it's part of a prank that has gone too far. Some irresponsible people might think it's funny to play such a cruel 'joke' on her without realizing the seriousness of their actions. However, this is still a very wrong and illegal behavior.
It might be a horror - themed story. The girl is tied and gagged, perhaps by some deranged person. The treadmill could be part of a sadistic plan, like she is forced to be near it for some psychological torture. The story could then be about her struggle to escape this terrifying situation.
There was a girl, Emma. She was in a park when some bad guys came up to her. They tied her up tightly and gagged her so she couldn't make a sound. They robbed her of her jewelry and phone. She felt so helpless. However, she remembered that she had a small tracker in her bag. Her family used it to find her location. When they got there, they saw the robbers and called the cops. The robbers were arrested and Emma was safe.
This is a very concerning situation. It could potentially be a sign of abuse or non - consensual activity. It might involve human trafficking or some form of coercion. The girl could be in serious danger physically and psychologically.
I don't think it's a common type of story. Most stories follow well - known genres and tropes. This 'girl tied gagged treadmill story' seems more like an out - of - the - box idea that might be found in very specific or experimental forms of literature or perhaps in some off - beat independent films.
However, if the story is written with malicious intent, such as to objectify or promote violence against women, then it is clearly unethical. Writers have a responsibility to use such potentially disturbing elements in a way that is socially and morally acceptable.
One possible story could be in a mystery or thriller context. Maybe the girl is a witness to a crime and the criminals tie her up and sock - gag her to keep her from screaming or alerting the police. Then, a brave hero comes along to rescue her.