When an unusually heavy winter storm blanketed much of Texas with snow, knocking out electricity to millions of homes and leaving many struggling to find clean water, one sector of the population was particularly vulnerable: inmates at the state’s largest county jail. Raul Carreon, a pretrial inmate at the Harris County Jail, said it became freezing cold and “pitch black” when the power went out at the lockup late on Feb. 14. Then, he said, they lost water pressure, so toilets wouldn’t flush, leading to “feces and urine backing up in the commodes.”