Relative and friends of the flight crew members of the Ukrainian 737-800 plane that crashed on the outskirts of Tehran, lay flowers at a memorial inside Borispil International Airport outside Kyiv, Ukraine, Jan 8, 2020. (EFREM LUKATSKY / AP)

A Ukrainian International Airline company worker reacts during a briefing at Borispil International Airport outside Kyiv, Ukraine, Jan 8, 2020. (EFREM LUKATSKY / AP)

The partner of Julia Sologub, a member of the flight crew of the Ukrainian 737-800 plane that crashed on the outskirts of Tehran, kisses a portrait of her at a memorial inside Borispil International Airport outside Kyiv, Ukraine, Jan 8, 2020. (EFREM LUKATSKY / AP)

Flowers, candles and a placard reading "Tehran-Kiev We mourn" are seen placed outside the Iranian embassy in Kiev on Jan 8, 2020, in remembrance of the victims of the Ukraine airplane that crashed in the Iranian capital Tehran. (SERGEI SUPINSKY / AFP)

A woman weeps during a service at Western University in London, Ontario, on Jan 8, 2020 for the four graduate students who were killed in a plane crash in Iran. (GEOFF ROBINS / AFP)

Rescue workers inspect the scene where a Ukrainian plane crashed in Shahedshahr, southwest of the capital Tehran, Iran, Jan 8, 2020. (EBRAHIM NOROOZI / AP)

Rescue workers search the scene where an Ukrainian plane crashed in Shahedshahr, southwest of the capital Tehran, Iran, Jan 8, 2020. (EBRAHIM NOROOZI / AP)