The Department of Corrections had required Hood to sign a waiver agreeing to stay 3 feet (0.9 meters) away from Smith’s gas mask in case the hose supplying the nitrogen came loose.

Smith began to shake and writhe violently, in thrashing spasms and seizure-like movements, at about 7:58 p.m. The force of his movements caused the gurney to visibly move at least once. Smith’s arms pulled against the against the straps holding him to the gurney. He lifted his head off the gurney the gurney and then fell back.

The shaking went on for at least two minutes. Hood repeatedly made the sign of the cross toward Smith. Smith’s wife, who was watching, cried out.

Smith began to take a series of deep gasping breaths, his chest rising noticeably. His breathing was no longer visible at about 8:08 p.m. The corrections officer who had checked the mask before walked over to Smith and looked at him.

The curtains were closed to the viewing room at about 8:15 p.m.