Facts

**Damage Substantiation in a Building Fire Case: Requirements for the Burden of Assertion and Substantiation** **Parties:** - **Appellant (Plaintiff):** [A.] Insurance, represented by Attorney Prof. Dr. Manuel Jaun. - **Respondent (Defendant):** [B. AG] , represented by Attorney Dr. Peter Heer. **Facts:** - The [C. AG] was the general contractor for the construction of the University of Applied Sciences [D.] in [U.] and the owner of the parts of this building to be taken over by the University of Applied Sciences. - The [B. AG] (defendant) concluded a contract for parquet flooring with the [C. AG] and awarded the work to a subcontractor, the sole proprietorship [E.] . - On April 10, 2013, a fire broke out on the construction site of the new campus building, as a result of which the Aargau Building Insurance (plaintiff) paid the [C. AG] an insurance benefit of over Fr. 19 million for the damage caused. - The plaintiff filed a lawsuit with the District Court of Frauenfeld on May 29, 2017, and applied to compel the defendant to pay it Fr. 15 million plus interest, as the cause of the fire was attributable to the defendant. - The District Court decided in an interim ruling that the defendant was liable in principle for the damage, while the Higher Court of the Canton of Thurgau dismissed the lawsuit due to insufficient substantiation of the damage. - The appellant filed an appeal in civil matters with the Federal Supreme Court against the decision of the Higher Court. **Reasoning:** The appeal of [A.] Insurance is directed against the decision of the Higher Court of the Canton of Thurgau, which dismissed the lawsuit due to insufficient substantiation of the damage. The Federal Supreme Court must examine whether the previous court correctly assumed insufficient substantiation of the damage. First, the Federal Supreme Court establishes that the prerequisites for a judgment on the merits are met and that the appeal has been sufficiently substantiated. The previous court has examined and affirmed the active legitimacy of the appellant. The respondent has not sufficiently substantiated its submissions, so it is not necessary to consider them. The Federal Supreme Court then addresses the question of the substantiation of the…