BAGHDAD — It was once a well-kept memorial for hundreds of Iraqi civilians who were killed by American bombs while they slept, a powerful symbol of suffering embraced by a dictator’s propaganda machine.

The destruction of the Amiriya bomb shelter, in a middle-class Baghdad neighborhood, on Feb. 13, 1991, at the outset of the Persian Gulf war, killed some 408 civilians in the worst way possible: Most were burned alive. It stands as the deadliest episode of civilian casualties in the painful history, now a quarter-century long, of the United States in Iraq.

For years, Saddam Hussein ensured that the event remained etched in the Iraqi collective memory, recalled in movies, songs, poems and ceremonies. The shelter was a required stop for visiting dignitaries and foreign correspondents in Mr. Hussein’s tightly controlled Iraq.

This week, 25 years later, the anniversary passed with almost no notice. An Iraqi Army unit now occupies the grounds of the shelter. The site is no longer open to the public, although the occasional survivors or family members of the dead are welcomed by soldiers and given tours.