An ongoing Associated Press investigation has uncovered deep, previously unreported flaws within the Bureau of Prisons over the last few years, including widespread criminal activity by employees, dozens of escapes, the free flow of guns, drugs and other contraband, and severe understaffing that has hampered responses to emergencies.

To some in this city, turning Alcatraz back into a prison would be a crime. “The Rock” closed 62 years ago, and San Francisco has channeled the public’s macabre fascination with life inside the notorious prison to turn it into one of the city’s top tourist attractions.