ここでは事故の危険があります。
I understand that the additional は to で and に is just to add a form of contrast. However, what I am confused about is that why is で used instead of に when the sentence contains "あります". To my understanding, に is most often used when あります is present.
Why is では used here in this case instead of には？
It's because the speaker grasps it as a phenomenon where some accident might happen.
For example, when you say 事故があった (there was an accident), what you really imagine is not so much a scene where something static is left there as one where people do something. That makes you lean toward で.
When actions are performed in a location often で is used. 家で寝ている, 公園で遊んでいる. So my guess (given the lack of context) in this case the writer was trying to emphasize accidents caused through activities in this location, rather than just the location itself.
