Over the Easter weekend in 2015, an audacious gang of criminals robbed a safe depository in London's Hatton Garden, the center of the UK's diamond trade. Shortly before, electrical cables under nearby Kingsway had caught on fire, disrupting the emergency services in the area. Coincidence? Alarms at Hatton Garden Safe Deposit Ltd went off, but the police ignored them. The burglars were caught on CCTV taking jewelry worth up to $200 million. They had used specialist equipment, taking days to tunnel through the walls of the vault. Within a month nine suspects had been arrested and valuables...