Cara Delevingne Says House Fire Would've Sent Her Spiraling If She Wasn't Sober

Cara Delevingne's reflecting on the fire that destroyed her home ... saying of course it's awful it all went up in flames -- but, it would've been way worse if she still drank and used drugs. The actress reflected on her tragedy in an interview with the Times of London published Sunday ... and, she says her sobriety kept her from falling off the deep end about the unfortunate incident. CD says, "It sucks but…