Inside El Salvador's secretive prison pits where notorious gangs are crammed together like livestock in shed-sized cells

Huddled together like cattle in a cage, some of the men of El Salvador's prison pits have languished in their rancid holding cells for more than a year. Designed only for temporary 72-hour stays, the sweltering cells, each 12 feet wide and 15 feet tall are crammed with more than 30 people - all veterans of the country's vicious war between the MS-13 and M18