Thursday (July 13) marks the 40th anniversary of New York City’s infamous 1977 electricity blackout. This was a pivotal moment in Hip-Hop history which ignited a surge in the formation of DJs and Rap crews throughout the genre’s birthplace.

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The two-day power outage caused much chaos for distressed New Yorkers who were already enduring an exhausting week-long heatwave, dodging a reputed serial killer nicknamed “Son of Sam,” and a record-high unemployment rate and bankrupt economy in the City. The anarchic situation resulted in countless tenement building arsons, violence and looting of local neighborhood stores. The lack of law enforcement presence in the streets brought the Big Apple to its nadir.

Hip-Hop culture burgeoned at the beginning of the 1970s in the desolate areas of the gang-dominated South Bronx. There were a limited number of DJ crews and MCs before the blackout. But following the sudden power outage on that fateful day in July 1977, young residents of neighborhoods throughout the affected areas broke into local electronics stores to scrap together brand new turntables, microphones, mixers, speakers, extension cords, and other necessary equipment to build their own soundsystems and become DJs and MCs. This exponentially increased the amount of Hip-Hop crews in the Big Apple.

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In the Vh1 2007 documentary NY77: The Coolest Year In Hell, legendary Hip-Hop artists, including Grandmaster Caz of the Cold Crush Brothers and his former DJ partner Disco Wiz, explain their experience during the blackout. “Everybody was like ‘Hit the stores,’ and everybody just started running all at once,” says Caz. “Now, some started running toward us. Me and Wiz, we had other ideas. We pull out the gun. We’re like ‘No no. Run that way. Don’t run this way. Run that way.’ Wiz stayed with the equipment, and I proceeded around the corner ’cause there was an electronics store, The Sound Room, and they had DJ equipment in there.” Caz explains they weren’t out simply to steal. “You couldn’t just say ‘I’m gonna be a DJ.’ You needed equipment, and that’s all I really wanted. I wasn’t trying to loot everything I could find.”

As the power went down in the City, the power of Hip-Hop ironically went up and spawned a cultural phenomenon that eventually became a billion-dollar industry.