What was the only bird that was taller than the ostrich?

Titanis Walleri. This bird is known from the early Pleistocene (Ice Age) of Florida. It is the last known member of the family Phorusrhacidae, a group of large, Flightless Birds which evolved in South America. This creature had an estimated body height of 3 meters (if it stood fully erect, and 2.5 meters in more normal situations). Titanis really had arms instead of wings.