Nabila Rehman, left, 9, watches as her brother Zubair reads a statement about the day their grandmother was killed by a U.S. drone strike in Pakistan, at a hearing in Washington, Tuesday. Jason Reed/Reuters

Nine-year-old Nabila Rehman rested her head on the table.

Nabila, a shy girl with startling hazel eyes and red streaks in her dark hair, along with her father Rafiq and 13-year-old brother Zubair have told the story of the day when a drone fell from the sky in their village in North Waziristan so many times that by Tuesday morning the tale was rote — even if this particular retelling was before U.S. lawmakers, at a briefing which was the first opportunity for members of Congress to hear directly from Pakistani victims of American drones.

It was Oct. 24, 2012, the day before the Islamic holy day of Eid-al-Adha in North Waziristan. Zubair, Nabila, their little sister, five-year-old Asma and some of their cousins were all in the fields beside their house as their grandmother, 67-year-old Momina Bibi, showed them how to tell when the okra was ripe for picking.

Zubair knew the drones were circling overhead; he has known their distinctive buzzing since he was even younger — a methodical zung, zung, zung, he says.

"It's something that even a 2-year-old would know," he said in Pashto, speaking to Al Jazeera through a translator. "We hear the noise 24 hours a day."

Before the missile hit, he remembers hearing two clicks, like a trigger being pulled. Suddenly, day seemed to turn to night as they were enveloped in darkness and heat. Their grandmother, Momina Bibi, was thrown 20 feet away and killed instantly.

Zubair, Nabila and the other children wounded in the attack were taken to a hospital. Zubair had shrapnel lodged in his leg — an injury that would take expensive laser surgeries to heal — while Nabila looked down to see her hand bleeding.

"I tried to bandage my hand but the blood wouldn't stop," she said. "The blood kept coming."

Momina Bibi's wounds were so severe that neighbors would not allow her sons to see the body, said Rafiq, a primary schoolteacher in Pakistan who was in town buying school supplies and sweets when the attack happened.

In the days and weeks after, Rafiq said the newspapers reported that militants had been killed in the strike. As far as he knows, his mother was the sole fatality. He has never received an answer from the Pakistani or U.S. governments about why she was targeted or whether the strike was a mistake.

The Rehmans traveled halfway across the world, from their remote village of Tappi, to tell their story and to urge lawmakers to put an end to the covert CIA program of "targeted killings" in Pakistan, Yemen and elsewhere. They also participated in an Amnesty International report about casualties of drones and a documentary by filmmaker Robert Greenwald, called Unmanned. According to the London-based Bureau of Investigative Journalism, 376 total strikes have taken place in Pakistan, killing up to 926 civilians and as many as 200 children.