Results of a series of tests on complete tubular trusses that showed diverse failure modes including buckling of members are summarized. The behavior of tube-to-tube joints in the trusses is discussed. Failures of joints were observed at loads close to the predicted joint capacities according to the formulas developed for the K-joint under axial brace loading. However, after buckling of members, the K-joints come under combined axial and bending loads and fail at a load lower than the joint capacity prediced by the formulas. Since the resistance of joints deteriorates due to combined load effects, joints should be designed to have a greater capacity than the buckling capacity of the members.