Douglas Harper's Etymology Dictionary
schlemazel
also schlimazel, "born loser," 1948, from Yiddish shlim mazel "rotten luck," from Middle High German slim "crooked" + Hebrew mazzal "luck." British slang shemozzle "an unhappy plight" (1889) is probably from the same source.\n\nA shlemiel is the fellow who climbs to the top of a ladder with a bucket of paint and then drops it. A shimazl is the fellow on whose head the bucket falls.
[Rep. Stephen J. Solarz (D.-N.Y.), 1986]