We first learned that it was a missile that took down a Ukrainian airliner over Iran because of this video showing the moment of impact.
All 176 people on board were killed.
To find out what happened to Flight 752 after it left Tehran airport on January 8th, we collected flight data, analyzed witness videos and images of the crash site, to paint the clearest picture yet of that disastrous seven-minute flight.
We'll walk you through the evidence, minute by minute, from the plane's takeoff to the moment it crashed.
It's the early hours of Wednesday, January 8.
Iran has just launched ballistic missiles at U.S. military targets in Iraq, in retaliation for an American drone strike that killed Iranian military leader Qassim Suleimani.
Iranian defenses are on high alert, on guard for a possible U.S. attack.
Four hours later at Tehran's Imam Khomeini International Airport, Flight 752, operated by Ukraine International Airlines, is getting ready for departure.
At 6:12 a.m., the plane takes off.
It flies northwest and climbs to almost 8,000 feet in around three minutes, according to flight tracker data.
It's following its regular route.
Up ahead are several military sites.
Until now, the plane's transponder has been signaling normally.
But just before 6:15 a.m., it stops.
This is where the first missile hits the plane.
Footage from a security camera near one of the military sites shows the missile launch.
It hits the plane and knocks out the transponder.
But the airliner keeps flying.
A security camera directly beneath shows what happens next.
A second missile launches, 30 seconds after the first.
And it explodes moments later.
A third video shows the impact.
Let's watch it again and slow it down.
Here's the missile, and here's the plane.
An Iranian military commander said a defense system operator mistook the passenger jet for a cruise missile.
(Speaking Persian) Unfortunately, because of the hasty decision of one person, this great disaster happened.
The plane is now on fire.
We don't know its precise path after 6:15 a.m.
But we do know that it turns back in the direction of the airport.
It continues flying for several minutes, engulfed by flames.
Around 6:19 a.m., a bystander films the plane slowly going down.
(Speaking Persian) The plane is on fire.
There appears to be a second explosion before the jetliner plummets outside Tehran about 10 miles from where the last signal was sent.
A security camera captures that moment, as the plane crashes toward it.
Here we see the immediate aftermath of the crash.
(Speaking Persian) Be careful of the electrical wires.
(Speaking Persian) Oh, oh it's an airplane.
As day breaks, another witness films the smoldering wreckage.
(Speaking Persian) Emergency workers are here helping people.
Debris is spread out over 1,500 feet along a small park, orchards, and a soccer field, narrowly missing a nearby village.
A large section of the plane looks badly charred.
More jet parts are found here.
And the plane's tail and wheels land over 500 feet away.
It is a gruesome scene.
The passengers' personal items — toys, clothes, photo albums — are scattered around.
After days of denials, Iran took responsibility for the crash, blaming human error at a moment of heightened tensions.