Dumb.
Pointless and misleading.
For a story that's "Based on actual events" you sure seemed to make up a whole bunch of BS.
Someone killed themselves by jumping in front of a subway, which in all actuality isn't an extremely uncommon event. Unfortunate and tragic, but not necessarily unheard of. I fail to understand how that is, "horror."
Ultimately, this wasn't what it promised to be, it wasn't a horror story in any sense. It was just a story of some woman killing herself, why you considered that even remotely a horror story is beyond me.
Even if these events did happen in their entirety, with the notable exception of the part where the woman runs up to him, (which was pointless and misleading if I might add), the reason for her killing herself with a smile on her face could easily be explained by a psychological disorder, were this a real event, which I seriously doubt.
Also, if he was the only witness, who was there to take a picture for the newspaper? Isn't that a contradiction?
Also, why would the police look for a witness to a suicide, it's not like it's a crime, this man would have had no connection to the woman, no explanation for why she did it, so the only valuable contribution that he might have had was to be able to tell the police that "she jumped in front of the subway." Which would have been blatantly obvious due to the fact that there's now the tattered remains of someone's corpse all over the tracks.
Also, if he was the only one there, how would the police know to look for a witness? No one knew he was there, because there was no one to see him.
And if it was some sort of security camera, would it really matter? So long as the guy didn't push the woman off into the subway, he wouldn't have provided any information to the police, so there was absolutely no reason to begin to "search" for the witness.
I don't understand, this makes no sense.
Anyways TLDR:
It's dumb and makes no sense.
The art was good though, except for the person, he didn't fit the background art style of the animation at all, which removed the audience from the sense of realism that you attempted to portray.