A Ukrainian Boeing 737-800 plane crashed shortly after takeoff from Iran on Wednesday, killing all 176 people on board. Here’s what to know.

A Ukrainian Boeing 737-800 plane crashed shortly after takeoff from Iran’s capital on Wednesday, killing all 176 people on board amid heightened tension in the region.
The plane crash occurred just hours after Iran launched ballistic missiles at two military bases in Iraq that house American forces, escalating tensions between the U.S. and Iran after an American drone strike killed Iran’s top military general, Qasem Soleimani.
It is unclear what caused the plane to crash minutes after the aircraft took off from Tehran. Initial explanations from both Ukraine and Iran contradict one another. Iranian officials have said the Boeing 737-800 crashed due to mechanical issues. Initially, the Ukrainian embassy in Iran agreed, blaming engine failure for the crash, but officials later backed away from that statement and said they will refrain from naming the cause of the crash while the investigation continues.
The plane crash brings renewed attention to Boeing, which continues to deal with the fallout of two deadly 737 MAX aircraft crashes within the past two years. Those incidents left 346 people dead, leading to worldwide grounding of the MAX. Boeing fired its CEO in December amid the continuing controversy.
Here’s what to know about the Ukrainian Boeing crash.
What happened in the plane crash?
The aircraft departed from Imam Khomeini International Airport in Tehran after being delayed for about an hour, according to the Associated Press. After taking off en route to Kiev, the plane did not go above 8,000 feet in the air, the AP reports, citing the flight-tracker FlightRadar24. A statement from Ukraine International Airlines confirms the aircraft ascended to 2,400 meters, just shy of 8,000 feet.
Data from FlightRadar24 shows the aircraft could have crashed within two minutes of taking off. While the cause of the crash remains under investigation, Qassem Biniaz, spokesperson for Iran’s Road and Transportation Ministry, told state-run news agency IRNA that one of the plane’s engines had caught on fire. The pilot then lost control of the plane, according to Biniaz.
Ukraine International Airlines officials said during a press conference that the crew working on the aircraft had been highly trained and that the plane was in good condition. The airline said it has suspended all flights to Tehran until further notice.
“Given the crew’s experience, error probability is minimal,” said Ihor Sosnovsky, vice president of operations for the airline.
The plane crashed southwest of Tehran, scattering debris across farmland that quickly became engulfed in flames. Video and photo footage from the site of the crash show rescue workers sorting through burned belongings and plane fragments.
Who are the victims?
The aircraft had 176 people on board, including passengers from around the world. Nine Ukrainian crew members were on the plane, according to Ukraine International Airlines. Ukrainian foreign minister Vadym Prystaiko said 82 Iranians, 63 Canadians and 11 Ukrainians, including the crew members, were on the flight, as well as 10 Swedish nationals, four Afghans, three Germans and three British nationals. The AP reports most passengers were flying to Kyiv on their way to other destinations.
Iranian officials have given slightly different numbers, saying the death toll is 177, with 147 Iranians and two Canadians on board, The New York Times reports.
Who is investigating the crash?
Ukraine International Airlines said in a statement that the investigation into the crash will involve the airline, aviation authorities in Ukraine and Iran, Boeing representatives and the National Bureau of Air Accident Investigation of Ukraine.
Although airliners’ black boxes are typically analyzed by their manufacturer following crashes, Ali Abedzadeh, head of Iran’s Civil Aviation Organization, said the aircraft’s flight data recorders would not be sent back to Boeing or the U.S., according to Iranian news agency Mehr.
“We will not give the black box to the manufacturer and the Americans,” Abedzadeh told Mehr, according to the Times.
Abedzadeh added that the aircraft’s pilots “did not contact the control tower” ahead of the crash and that the flight crew had not reported any technical problems.
Ukrainian President Volodymyr Zelensky wrote in a Facebook post that a group of government representatives, including those from the ministries of defense, foreign affairs and international affairs, will travel to Iran to investigate the crash and to identify and repatriate the bodies of Ukrainian nationals killed in the crash.
How has Boeing responded?
Early Wednesday, Boeing tweeted that its “heartfelt thoughts” are with those affected by the crash.
“We are in contact with our airline customer and stand by them in this difficult time,” the tweet read. “We are ready to assist in any way needed.”
How have world leaders responded?
Zelensky returned to Ukraine from a visit to Oman following the crash and has posted frequent updates to Facebook regarding the investigation. In his first post, Zelensky extended condolences to the families and loved ones of the passengers and crew on board.
Canadian Prime Minister Justin Trudeau said he was “shocked and saddened” about the crash, which killed 63 Canadians.
“Our government will continue to work closely with its international partners to ensure that this crash is thoroughly investigated, and that Canadians’ questions are answered,” he said in a statement. “Today, I assure all Canadians that their safety and security is our top priority. We also join with the other countries who are mourning the loss of citizens.”
Write to Mahita Gajanan at mahita.gajanan@time.com.