Leanne Nasser was a bright-eyed Arab Israeli teenager, in Istanbul with friends for New Year’s despite her father’s concerns about safety. Fatih Cakmak, who survived a bomb attack only weeks ago, was hired to work security for a popular nightclub.

Both were among those who died early Sunday when a gunman, brandishing an assault rifle, stormed Istanbul’s famed Reina club on the banks of the Bosporus, gunning down unsuspecting New Year’s revelers in a rampage that was one of the city’s worst mass killings in recent memory.

The assailant remained at large Sunday night and unidentified except for blurred glimpses of him in security camera footage that showed gunshots sparking off the pavement and victims crumpling to the ground. Thirty-nine people were killed, many of them foreigners, in the latest in a string of assaults that have roiled Turkey as it battles insurgents at home and across the border in war-torn Syria. At least 70 people were wounded.