By day, they faced torture and the constant threat of execution at the hands of their ISIS captors. At night, they used a stolen piece of jagged metal to scrape the crumbling wall of their prison until last week, when they had fashioned a hole big enough to squeeze through. A 30-year-old man who was one of 20 who fled the jail in Tabaqa, Syria, days later recounted the daring escape to the Syrian activist group Raqqa is Being Slaughtered Silently. As the prisoners poured out of the hand-hewn tunnel, running all directions into the night, a siren and the...