Iranian journalist Niloufar Hamedi specialized in covering women’s issues. So when her editor noticed an Instagram post about a young woman in a hospital in bad shape after being arrested for violating the country’s strict Islamic dress code, Hamedi headed straight there.

She found relatives of the woman, Mahsa Amini, 22, holding one another tightly in a fluorescent-lit ward inside Kasra Hospital in Tehran, Iran. She snapped a picture and posted it on Twitter — and then it went viral. That was Sept. 16, the day Amini died.

Anti-government protests soon spread around Iran, igniting chants of "Women, life, freedom,” and they shook the country for many months. But Hamedi, 30, was not there to witness it: She had been arrested days after Amini’s death.