In the 2002 TV film "It's a Very Merry Muppet Christmas Movie", there's a part where an angel shows Kermit an alrernate reality where he was never born. For whatever reason, the editors didn't really think about it, and continued to use footage with the twin towers still standing for this scene; however, they aren't there in his original universe. Therefore, something that Kermit did in his life, did in fact cause 9/11 in Muppet lore.
𝓓𝓮𝓪𝓻 [streamer name] , 𝓘 𝓻𝓮𝓰𝓻𝓮𝓽𝓯𝓾𝓵𝓵𝔂 𝔀𝓲𝓵𝓵 𝓫𝓮 𝓻𝓮𝓼𝓲𝓰𝓷𝓲𝓷𝓰 𝓯𝓻𝓸𝓶 𝓫𝓮𝓲𝓷𝓰 𝓪 𝓫𝓮𝓵𝓲𝓮𝓿𝓮𝓻 𝓪𝓷𝓭 𝔀𝓲𝓵𝓵 𝓫𝓮 𝓳𝓸𝓲𝓷𝓲𝓷𝓰 𝓽𝓱𝓮 𝓭𝓸𝓾𝓫𝓽𝓮𝓻𝓼 𝓲𝓷 𝓭𝓸𝓾𝓫𝓽𝓲𝓷𝓰 𝔂𝓸𝓾𝓻 𝓪𝓫𝓲𝓵𝓲𝓽𝓲𝓮𝓼.