Three days before the blast, a 155mm illumination shell, commonly used by the Israeli military and not in use by Palestinian militias, was fired into the Al-Ahli Hospital. Hospital administrators said that they had received warnings from the IDF telling them to evacuate.

Israeli and U.S. intelligence officials believe that a projectile captured on videos shortly before the Ahli Arab Hospital explosion was a Palestinian rocket. @nytimes Visual Investigations found that this object was launched from Israel, and likely unrelated to the deadly blast.

Read here:

An IDF spokesperson went on CNN and the BBC with a printed-out screenshot from an Al Jazeera livestream showing this projectile, claiming it was the rocket that hit the hospital. We also believe that American officials are incorrectly assessing this to be a Palestinian rocket.

We geolocated five videos that showed this projectile launch from the north, south, east and west. By drawing lines of perspective, three of which can be seen here, we assessed that this project was launched from near the Israeli city of Nahal Oz.

We cannot say with confidence what exactly this projectile is, but we know that there is at least one Iron Dome launch site in nearly the same location that overlaps from the sight lines we drew from the five videos. This site was still present in satellite imagery this year.

This projectile may have been launched in reaction to barrages of rockets from Gaza. A timeline: 1) Palestinian rocket barrages, followed shortly by 2) Israeli projectile launch 3) 17.5 seconds in air before the projectile detonates 4) Explosion at the hospital 7 seconds later

About 25 seconds passed from the last Palestinian rocket fired and Israeli projectile, to the hospital explosion. There is no visual evidence we have found that directly links these events to the blast at the Al-Ahli Arab hospital.

The projectile launched from Israel detonates at least two miles from the hospital, and 25 seconds passed from when the final Palestinian rocket was launched in these videos and the hospital explosion.

The situation in the area around the hospital was chaotic that evening. The Al Jazeera livestream of the scene, plus other videos we reviewed, shows at least two large explosions near the hospital in the minute before the deadly blast.

The IDF told The Times that it was striking Gaza City that evening, but said that it was not in an area that would endanger the hospital.

Our analysis does not answer what actually did cause the blast or who was responsible, but it does undercut one of the most-publicized pieces of evidence used by both American and Israeli officials.

Read our investigation below. Amazing work from the whole team on this, include an ultra-keen eye on video footage from @NatalieReneau & Alex Cardia, and reporting from @riley_mellen, @heytherehaley, @ckoettl, and @julianbarnes.

Lastly: a shout-out to the first person to publicly lay out the case that this may have been an Israeli missile interceptor and not a Palestinian rocket: @ArchieIrving2. He had it on October 19th.

Forgot Alex's Twitter! He's at: @ajcardia

Addendum to this thread: If this were an Iron Dome interceptor, what was it intercepting? A possible answer below from Riley. In the IDF's map showing rocket barrages at 6:59pm, there's one stray rocket that goes in the direction of the mid-air detonation

Le Monde corroborated the geolocation of the launch site to Israel:

Extended footage from the Channel 12 broadcast that we used in our investigation:

Very good @washingtonpost analysis on the hospital blast, including further confirmation of the Israeli launch site for the possible Iron Dome interceptor seen in the various videos. They also show some satellite imagery of the likely Iron Dome site.

HRW just put out their investigation a month after the explosion. Not much new. The investigation ultimately point to a Gaza-launched rocket as the most likely culprit. (They also confirm an Israeli missile interceptor was fired, separate from the blast)

wow for some reason they were able to find israeli munitions in this case. wonder why they magically couldn't find anything in the courtyard