A pressure release device for an internally pressurized fluid container has a dome-shaped inwardly concave closure element circumferentially joined to one end of the tubular container side wall. The closure element is deep drawn of tempered steel, with a circular central area spaced from an annular outer area by an annular intermediate area traversed by radially extending L/u/ ders Lines. A tab member is located in the central area. The tab member is partially circumscribed by a single weakened circular line of reduced material thickness, with the ends of the line being separated by a connecting area of substantially undisturbed material thickness and strength. The closure element has a structural integrity which reacts to an increase in fluid pressure in the container above a prescribed level by undergoing at least a partial eversion extending from the annular outer area, across the annular intermediate area into the circular central area to initiate a fracture of the closure element along the weakened line of reduced material thickness. The connecting area remains intact during any resulting outward deflection of the tab member occasioned by fluid escaping from the container through the fracture.