In 1988, the US Navy accidentally killed 290 civilians when it shot Iran Air Flight 655 out of the sky.

In America, the attack has largely been forgotten, but it's never left Iran's national consciousness, and many believe that it wasn't an accident.

Iranian President Hassan Rouhani referred to the tragic mistake on Twitter two days before Ukrainian Airlines Flight 752 crashed after leaving Tehran.

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In 1988, the US Navy accidentally shot an Iranian plane out of the sky, killing 290 people.

The USS Vincennes was in the middle of a skirmish with Iranian gunboats when it saw Iran Air Flight 655 on its radar and confused the Airbus 300 for a fighter jet. After it failed to respond to the Navy's distress signals, the US shot it down with a missile. Everyone on board was killed.

Yet despite this shocking mistake, it's often forgotten in the US. In Iran, it remains a national outrage. Many don't believe that it was a mistake, but a warning from the US.

On Monday, Iranian President Hassan Rouhani referred to the tragedy via a tweet with the hashtag #IR655.

Two days later, Ukrainian Airlines Flight 752 crashed after leaving Tehran, killing all 176 people on board. Multiple reports on Thursday said evidence indicates Iran accidentally shot down Flight 752 shortly after it launched a missile attack on US and coalition forces in Iraq.

Here's the story of Iran Air Flight 655.