The failure was caused Causation by the failure of O-ring seals used in the joint Collaboration that were not designed Create_artwork to handle the unusually cold conditions that existed Presence at this launch .

The seals ' failure caused Causation a breach in the SRB joint , allowing Preventing_or_letting pressurized burning gas from within the solid rocket motor to reach Arriving the outside and impinge upon the adjacent SRB aft field joint Collaboration attachment hardware and external fuel tank .