Report entitled "All in the Species":
In one case six dogs of beagle, dachshund, and terrier breeds (all small dogs) killed and partially consumed an 81 year-old woman!
Other small dogs have killed people. Pediatrics (1982) reports of a Yorkshire terrier that killed a child. Public Health Reports (1977) reports of a dachshund that killed a 7 month-old boy when the mother left them alone together momentarily.
Of course the report goes into deaths caused by pit bulls and large dogs, as well:
The award for the most non-fatal bites goes to cocker spaniels and chow dogs. Next on the list of fatal bites were German shepherds at 9; huskies at 7; malamutes at 6; Doberman pinschers, rottweillers, and wolfdogs at 5; Great Danes and Saint Bernards at 4. The rest are hounds, bulldogs, chows, cocker spaniels, labs, retrievers, boxers, and English sheepdogs.
Disclaimer: I own a beautiful Rottie/German shepard mix that is the most tolerant, sweet-natured, friendly dog I've ever had.