Kermit the frog caused 9/11. In the 2002 TV film "It's a Very Merry Muppet Christmas Movie", there's a part where an angel shows Kermit an alternate 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.
𝓑𝓻𝓸𝓽𝓱𝓮𝓻 𝓘 𝓻𝓮𝓬𝓮𝓲𝓿𝓮𝓭 𝔂𝓸𝓾𝓻 𝓶𝓮𝓼𝓼𝓪𝓰𝓮 𝔀𝓮𝓵𝓵. 𝓘𝓽 𝓮𝔁𝓬𝓲𝓽𝓮𝓼 𝓶𝓮 𝓽𝓸 𝓲𝓷𝓯𝓸𝓻𝓶 𝔂𝓸𝓾 𝓪𝓫𝓸𝓾𝓽 𝓪 𝓬𝓸𝓬𝓴 𝓻𝓮𝓼𝓮𝓻𝓿𝓮, 𝓯𝓻𝓮𝓽 𝓷𝓸𝓽, 𝓬𝓸𝓬𝓴 𝔀𝓲𝓵𝓵 𝓫𝓮 𝓼𝓮𝓷𝓽 𝔂𝓸𝓾𝓻 𝔀𝓪𝔂 𝓼𝓸𝓸𝓷.