Influential American artist Mike Kelley was found dead yesterday at age 57, in what police say appears to be a suicide. A friend told investigators he had been depressed following a recent breakup, the New York Times reports. Kelley specialized in large-scale pieces, often incorporating sculpture, video, or performance, and his work tended toward what the art world terms "abjection"—a preoccupation with visceral, shocking, gross-out imagery. He's been featured extensively in gallery shows, and will be included in the upcoming Whitney Biennial. One of his pieces was also used as the cover of the Sonic Youth album Dirty in 1992. (More Mike Kelley stories.)