"Jet Fuel Can't Melt Steel Beams" is an assertion made by September 11th, 2001 attack conspiracy theorists that the burning fuel from crashed planes would not have been able to melt the supporting beams of the World Trade Center. The claim is widely mocked online for being based on flawed evidence.
On April 13th, 2005, the first installment of the Loose Change film series was released, which argued that the September 11th, 2001 attacks were orchestrated by the United States government. The film claims that the burning fires within the World Trade Center towers would not have been hot enough to compromise its structural integrity, alleging that a controlled demolition actually brought down the two buildings.
On April 7th, 2010, Popular Mechanics published an article titled "Debunking the 9/11 Myths: Special Report – The World Trade Center," which provided evidence that burning jet fuel can melt steel. On November 8th, 2014, Redditor Sir-SmokesALot submitted a version of the "I Wish I Could Talk to Ponies" webcomic titled “Things a pony would say,” in which a horse informs a young girl that “jet fuel can’t melt steel beams" (shown below). In three months, the post gained over 4,400 votes (92% upvoted) and 950 comments on the /r/funny subreddit.
On January 27th, 2015, Redditor Lust_In_Phaze submitted a post titled "The Revelation," featuring a photo of a man with legs resting on his shoulders along with the caption "When you're about to cum but you realize jet fuel can't melt steel beams" (shown below, left). In the first month, the post gathered upwards of 5,000 votes (92% upvoted) and 500 comments on the /r/BlackPeopleTwitter subreddit. On February 5th, Redditor JollyToaster uploaded an edited four-panel comic featuring cartoon character Winnie the Pooh telling an Illuminati pyramid that "jet fuel can't melt steel beams" to the /r/funny subreddit (shown below right).
"Dank memes make the world go 'round it seems, jet fuel can't melt steel beams."