In love, engaged, dead

A young student falls to her death on the day of her engagement at her wealthy father's penthouse. Was it an accident, or rather a cold-blooded murder? You slip into the role of retired detectives. Herbert Kogler, an old acquaintance of yours, has lost his only daughter. He is the owner of the largest and richest real estate company in the city. In the city center, there are entire quarters that exclusively house properties in his possession. This includes a luxurious, two-story penthouse where his daughter intended to celebrate her engagement to her great love with friends on the day of her death. In the middle of the night, she fell down the stairs there and landed with severe consequences. She was dead on the spot. Herbert Kogler has asked you to shed some light on the situation parallel to the police. Of course, you want to comply with this request - even if you know that it will be anything but easy. You are retired, so technically you are not allowed to investigate officially. If you want to get reports from specialists, you will have to use your contacts.