Britain is in shock after UK Labour MP Jo Cox was shot and stabbed to death on the streets of her West Yorkshire constituency.
She was a mother of two young children, a wife, and a campaigner for the rights of migrants and refugees.
A man has been arrested by police, but the motives behind the brutal attack which left her bleeding in the street remain a mystery.
One witness says he heard two shots -- initially, he thought they were being fired randomly.
When police arrived, the suspect was handcuffed and dragged to the side of the road, pinned down with his face pressed to the concrete.
He's been named by neighbours as Tommy Mair. He lived nearby, a reclusive gardener and a constituent of Ms Cox.
"It was just sort of the calmness, everyone was running and screaming, and he just walked past like he had a purpose," a witness says.
Ms Cox's husband tweeted a picture of his wife outside their London home, a riverboat on the Thames. It's a boat which has since become a memorial.
In a statement Brendan Cox said:
"Today is the beginning of a new chapter in our lives. More difficult, more painful, less joyful, less full of love."
Ms Cox had barely been an MP for year, a strong advocate of refugee and migrant rights.
Before politics she had been an aid worker in developing countries.
She was widely considered one of Labour's most promising MPs
"She leaves behind two young children," UK Labour leader Jeremy Corbyn says.
"They can be proud of what she did, and they can be very proud of everything that she stood for."
Ms Cox had been a big part of the campaign for the UK to remain in the EU, just yesterday joining a flotilla on the Thames.
Upon news of her death, campaigning for the referendum was suspended.