This is one case where the language might help. In the original German1, he writes:
1 Die Welt ist alles, was der Fall ist.
1.1 Die Welt ist die Gesamtheit der Tatsachen, nicht der Dinge.
1.11 Die Welt ist durch die Tatsachen bestimmt und dadurch, daß *alle* Tatsachen sind.
The key word in 1.11 is bestimmt (determined, selected, decided, or caused). This is not to be read as a Tatsache (fact) itself, because by using the word bestimmt he indicates a distinction between what a fact is, and what the case (der Fall) is. To say something is determined is like to say (in the language) that something has been caused to be so. To be determined is not itself an abstract fact (Tatsache), but an immanent constituent of the way things are.
In essence Wittgenstein's opening boils down to the incontrovertible statement that the way things are, are the way they are, because of the facts that make them so. This principle cannot be unpacked as a fact itself, or it would be a fact determining a fact. That it was determined by a fact makes it a case of how things are, not a fact itself.
All of this is borne out by the rest of the section, which reads
1.12 Denn, die Gesamtheit der Tatsachen bestimmt, was der Fall ist und auch, was alles nicht der Fall ist.
1.13 Die Tatsachen im logischen Raum sind die Welt.
1.12. "Then, the totality of all facts determines what the case is and also, what isn't the case."
1.13. "The facts in scope of logic are the world."
1 Kenny, A., Wittgenstein, L., 1995. Ein Reader. Reclam, Philipp, jun. GmbH, Verlag, Stuttgart. p. 9.