Authorities in Pittsfield were working Tuesday night to recover the body of a man who was sucked down the drain of a dam there while swimming, said Pittsfield Deputy Fire Chief Mark Cancilla. The victim, a man in his 20s from California, was swimming with a friend Tuesday afternoon when the 4-foot wide drain’s current caught him, Cancilla said. Using underwater cameras, authorities found the body wedged in the drain, and they were working to redirect the water’s flow long enough for divers to extract it, Cancilla said. Authorities have not yet released the man’s identity. Cancilla said there are signs posted in the area warning residents not to swim there.