How the crash of Ukrainian Flight 752 unfolded, from the plunge that killed 176 people, to allegations it was shot down by an Iranian missile

WEDNESDAY: The plane crash took place against a backdrop of heightened tensions between the US and Iran, which kicked off when the US assassinated Iranian general Qassem Soleimani.

This prompted Iran to retaliate, and it fired more a dozen missiles at US forces in Iraq early in the morning of Wednesday, January 8.

Multiple reports said US officials believe the strikes were intended as warnings and that Iran may have been shooting to miss.

Then, at 6.12 a.m. local time, Ukraine International Airlines Flight 752 took off from Iran's Tehran Imam Khomeini International Airport, according to flight tracking software.

The plane was going to Kyiv, Ukraine's capital.

The plane was on fire before it crashed, according to alleged video footage of the crash and Iran's initial report released the day after the incident.

The report was released on Thursday, the day after the crash. It is a preliminary report, citing eyewitnesses, while the final report will likely take at least a year to compile and publish.

The plane lost contact two minutes later, according to flight trackers. Iran's report said it turned back in the direction of the airport and then, an unknown number of minutes after taking off, it crashed.

Iran's official news agency, IRNA, posted a picture that confirmed the crash as information started to emerge.

A spokesperson for Iran's emergency services told state media that there had been no survivors, while Iran's foreign minister shared a list of the nationalities on board.

They included 82 Iranian citizens, 63 Canadian citizens, and 11 Ukrainian citizens.

Vadym Prystaiko said in a tweet that there were also 10 Swedish citizens, four Afghan citizens, three British citizens, and three German citizens.

Iran does not acknowledge dual citizenship, and has in some cases has listed most of the Canadian figures as Iranian, leading to some confusion over the numbers.

On Wednesday morning, Iranian authorities immediately attributed the crash to technical problems with the plane, dismissing the idea of a terror attack. Ukraine's embassy in Tehran cited engine failure.

Qassem Biniaz, an official at the Iranian Ministry of Roads and Urban Development, told state news agency IRNA that an engine caught fire and the pilot was unable to regain control, The New York Times reported.

But Ukraine International Airlines said in a statement later on Wednesday that the plane was still new, having only been delivered in 2016, and had scheduled maintenance just days earlier. It also pointed to the experience of the crew.

It said the plane had been delivered as new from Boeing.

Video footage shared by the semi-official Iranian Students' News Agency appears to show the plane on fire in the air before hitting the ground and filling the sky with flames.

نخستین ویدئو از سقوط هواپیمای اوکراینی اطراف شهریار pic.twitter.com/M3bZiLLryQ

As US markets opened, Boeing's shares fell, with extra scrutiny facing the company as it was already dealing with the fallout of two fatal crashes by its 737 Max planes.

$4.3 billion of market value was erased the day of the crash.

The company said it was ready to help with any investigations as needed, and sent sympathies to families.

Ukraine's embassy in Tehran then deleted its statement that cited engine failure as the cause of the crash, and said that it was instead too early to say what had happened.

According to Reuters, the embassy said the earlier statement was based on preliminary information but was not official, and that Iranian authorities had asked the embassy to remove it.

Ukrainian President Volodymyr Zelensky said he was opening criminal proceedings, and warned against "speculation or unchecked theories regarding the catastrophe."

Iran suggested that there could be political disruption to the typical international after-crash process, saying it would not hand over the plane's black box to Boeing, as would be typical.

Ali Abedzadeh, the head of Iran's civil aviation authority, told semi-official news agency Mehr that Iran would not give the black box to Boeing, according to Reuters.

Speculation had begun to swirl over the cause of the crash, even as some experts said it was too early to draw any conclusions.

The confusing statements from Iran, as well as the airline's belief in its crew's experience, helped fuel suspicion.

THURSDAY: Iran released its initial report into the crash on Thursday morning — an unusually quick turnaround for this type of preliminary report.

It said the plane was on fire and turned back in the direction of the airport before it crashed, and that the pilots did not send any crisis communication.

It said the flight suffered an unnamed technical issue after takeoff.

That same morning, Ukraine revealed that it was investigating whether the plane could have been brought down by a missile or terror attack.

The secretary of Ukraine's National Security and Defense Council said Ukraine is also considering if the plane was destroyed by an anti-aircraft missile, brought down in a terror attack, or collided with an object in the sky.

Ukraine did not dispute Iran's idea that the plane was brought down by a technical issue, but said it wanted to explore all options and cited unconfirmed reports of debris from a Russian missile.

Late on Thursday morning US time, multiple reports were released claiming that US officials believe it is likely that the plane was shot down by an Iranian surface-to-air missile.

US officials told Newsweek, Reuters, and other outlets that the incident was likely an accident, as Iran's anti-aircraft systems were likely on high alert at the time of the crash, poised for a US retaliation following the Iranian attacks on US bases.

These reports were then confirmed by other outlets.

Iran denied the reports, maintaining that it would not be possible for the plane to have been shot down by its missiles because the plane was flying too high.

Fars News Agency reported that an Iranian aviation official said it would be "scientifically impossible" because the plane was flying at 8,000 feet.

But that 8,000 feet is within the range of the 29 Tor M1 missile defense batteries that Iran bought from Russia in 2005.

Canadian Prime Minister Justin Trudeau said that intelligence from both Canada and its allies suggested Flight 752 was shot down by an Iranian missile, and called for a "thorough and credible investigation."

Trudeau said that "Canadian expertise when it comes to air tragedies" is "world-class."

"We have lots to contribute, and we have lost much," he said of the 63 Canadians killed in the crash, many of whom were in transit back to Canada from Iran.

US President Donald Trump did not comment on the supposed intelligence, but said he suspected that the plane might have been shot down.

"I have my suspicions. I don't want to say that because other people have their suspicions also," he told reporters Thursday afternoon.

"Some people say it was mechanical. I personally don't think that's even a question."

The New York Times then said that it had verified a video that appeared to show the moment a missile struck the plane.

The video had been circulating on social media, and the Times said the video appeared to show the missile hitting the plane at the location the signal from the plane's transponder was last received, and that there was a small explosion but the plane remained flying for several minutes.

This is consistent with Iran's report on Thursday, which said the plane had turned back to the airport before crashing.

UK Prime Minister Boris Johnson was the next world leader to chime in, saying that British intelligence also suggested that Flight 752 had been shot down.

"There is now a body of information that the flight was shot down by an Iranian Surface to Air Missile. This may well have been unintentional."

He also said there were four UK citizens on board, rather than just the three first identified by Iran's foreign minister.

Having plunged on Wednesday, Boeing's stock traded higher on the news of a possible missile strike.

With intelligence reports suggesting the plane was hit by a missile, the idea that the crash was down to a technical issue with the plane was weakened, and Boeing's possible culpability lessened.

Boeing stock traded as much as 3% higher on Thursday.

Images and reports then emerged from the crash site that suggest bulldozers are being used on the site, potentially damaging some evidence.

Images and reports from the crash site show at least one bulldozer working in the debris at the site.

FRIDAY: Early Friday morning, Iran repeated its assertions that the plane had not been taken down by one of its missiles.

Government spokesman Ali Rabiei called the idea Iran downed the plane a "big lie."

"It is unfortunate that the psychological operation of the US government, and those supporting it knowingly and unknowingly, are adding insult to the injury of the bereaved families and victimizing them for certain goals by propagating such fallacies," he said.

Ali Abedzadeh, the head of Iran's civil aviation organization, also said on Friday than could say with "certainty that no missile has hit this airplane."

And Hesameddin Ashena, an adviser to Iran's president, said on Friday that Persian-language media had been "warned" against repeating the "psychological warfare" Iran said was being carried out by Western nations.

Iran then said that it would allow Boeing representatives to examine the plane's black boxes, in an apparent reversal of its previous position.

A government spokesman said Boeing could send a representative "to participate in the procedure of examining the black box."

Iran then said that it had invited investigators from the US, Ukraine, Canada, and France, well as Boeing, to join the investigation.

These countries had signaled their willingness to join, but Iran had not previously confirmed their involvement.

Iran also said that it wants to look at the plane's black boxes itself, but was willing to send them to another country for analysis if it faces technical problems in doing so.

Abedzadeh said in a press conference on Friday afternoon: 'If we can do it ourselves, we will."

"If not, we will definitely ask for assistance from other countries," he said.

Iran has noted some damage to the boxes that may make examination more difficult, and said that extracting the data could take a month or two.

The European Commission has called for an "independent and credible" probe into the Iran crash.

Eyewitnesses claimed that debris is being removed from the crash site, and that scavengers were removing pieces as it was not secured.

CBS News reported that "apparent scavengers" were going through the debris before Ukrainian investigators arrived.

The network's foreign correspondent Elizabeth Palmer said there was "no security."

CNN cited eyewitnesses who said the large debris pieces have been removed, and experts told the outlet that this was very unusual in such an early phase of the investigation.

Russia's deputy foreign minister then said there is "no basis" to claim that Iran is responsible for the crash, dismissing the idea as "games" until more investigations are done.

News agency TASS reported that Sergei Ryabkov said that: "There is no basis to come out with explosive statements at this stage, I'm strongly convinced that trying to score political points based on this terrible human tragedy is unacceptable."

He was responding to Trudeau's statements.

"The experts need to analyze the situation and make their conclusions, so starting such games is at the very least undignified," Ryabkov said.

"There is no basis, I'm sure of it, to make loud statements of this kind at this stage."

Ukraine's Zelensky, who had called on other countries to release their data as the idea the plane was shot down has not been confirmed, said he had received "important data" from a meeting with US representatives, but did not elaborate.

It is likely to take months, if not years, to establish exactly what happened on Flight 752 on Wednesday, January 8.