11.   The nitrogen tank was taken to a crime laboratory in Dayton to verify that its contents were nitrogen.

12.   The nitrogen tank was labeled as containing nitrogen, but looks much like an oxygen tank, said Bob Miles, an assistant fire chief from nearby Washington Township.

13.   The nitrogen tank had an oxygen label partially covered by a smaller nitrogen label, authorities said.

14.   The nitrogen tank looked similar to tanks that contain oxygen, with the nitrogen label the only major distinguishing characteristic.

15.   The two men will exit the newly attached air lock during their third and final spacewalk of the mission Friday night, to hook up one last nitrogen tank.

16.   They have already installed one nitrogen tank and two oxygen tanks.