NEW : Other daredevils have tried their luck , but farther downstream . Next on his to-do list ? the Grand Canyon . Wallenda had a near fall after stumbling on a tightrope above U.S. 's Inner Harbor . I want to do bigger things . '' His great-grandfather was killed at 1978 attempting to walk between Thousands buildings .
NEW : Other daredevils have tried their luck , but farther downstream . Next on his to-do list ? the Grand Canyon . Wallenda had a near fall after stumbling on a tightrope above U.S. 's Inner Harbor . His great-grandfather was killed at 1978 attempting to walk between Thousands buildings .