From the New York Times, I'm Sabrina Tavarnese. This is The Daily.

Today, a Times investigation reveals one of the largest civilian casualty events of the war against the Islamic State.

I spoke to my colleague, Dave Phillips, on how the system designed to bring this to light ended up keeping it hidden.

It's Monday, November 15th.

Dave, where does the story start?

The story starts March 18th, 2019, in a big Air Force Combat Operations Center in Al Yudid in Qatar.

And there we have, it almost looks like Mission Command for NASA.

You have banks of computers, big screens, all of them watching the Air War against the Islamic State.

The coalition had over years and thousands of air strikes basically clawed away its territory.

Once the group had controlled millions of acres, but by that day in March, they only controlled about one square mile of dirt fields pressed against the Euphrates River in Syria.

And on this day, a lot of people in the Command Center are watching a drone that was flying up overhead.

Now, what they saw was a field that was just littered with a tangle of cars and makeshift tents of debris of the leftovers from weeks of combat.

But also within there was a lot of people.

And the drone hovered over and focused in on a group of women and children who had found refuge down by the river against a steep sandbank.

The drone, it lingered for several minutes, slowly circling with its cameras focused on these folks, either sleeping or just laying down low to take cover from whatever combat might be coming.

And the people in the Operation Center were calmly watching this when suddenly they saw something cross their screens that they didn't expect.

An American at 15 attack jet came right through and dropped a large bomb dead center into this group of women and children.

And there was this shuddering blast that basically filled the whole view of the drone camera and gulfed all of these people, killing nearly all of them.

So there's all these people in the Operation Center that don't know what the heck is going on and they scramble to try and piece things together.

They're chatting with each other over secure chat logs just trying to figure it out.

And one of them immediately types out who dropped that meaning the bomb and another one says we just dropped on 50 women and children.

So what are those people in the room do?

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