Did a Wall Street Journal article state that it was "an American MK-84" bomb that hit the Gaza hospital on October 17, 2023? No, that's not true: The newspaper did not publish that. The only supporting "evidence" in the social media post that made this claim was a photo from 1991 unrelated to the October 2023 Hamas-Israel conflict.
The Wall Street Journal: 'The bomb that was dropped on the hospital was an American MK-84.' This bomb is precision-guided, largest in MK family and has about 950 kg weight.
This is what the post looked like on X at the time of writing:
MK 84 stands for Mark 84, which is an American-made general-purpose bomb.
Like many major media outlets in the world, The Wall Street Journal (WSJ) did cover the explosion in the Al-Ahli Baptist Hospital in Gaza on October 17, 2023, as the story unfolded. But it did not make the claim attributed to it by the post on X.
(Source: Google screenshot taken on Thu Oct 19 17:19:10 2023 UTC)
According to the reverse image search tool TinEye, the image attached to the post on X has been online at least since 2009:
(Source: TinEye screenshot taken on Thu Oct 19 18:09:05 2023 UTC)
It was used to illustrate, for example, a Japanese-language article on Wikipedia (archived here), as of this writing. The detailed description available for this file stated that the photo was taken over three decades before the October 2023 Hamas-Israel conflict:
(Source: Wikipedia screenshot taken on Thu Oct 19 17:31:04 2023 UTC; the page was automatically translated to English by Chrome)
The image has been available on a stock photo website for the past 10 years.
The claim that an MK 84 was the munition used to hit the Gaza hospital also appeared in a video (archived here) published on the YouTube channel of the Turkish state-run news agency Anadolu. It contained a vertical clip split into two parts. The top half claimed to show some daylight explosion resulting from the use of an MK 84 bomb; the bottom part supposedly showed the nighttime blast in the Gaza hospital. The caption compared the sound in the two videos. However, it lacked concrete evidence such as crater analysis or close examination of the post-blast debris tying MK 84 to the blast in the Gaza hospital.
(Source: YouTube screenshot taken on Thu Oct 19 17:46:17 2023 UTC)
As of this writing, there is no publicly available information proving that this particular bomb caused the blast.
While Israel and Palestinians accused each other of the attack, President Joe Biden said that the evidence presented by the Pentagon suggests that Israel was not responsible for this particular explosion.
Other Lead Stories fact checks related to the Hamas-Israel conflict are here.