Following severe ischemic or toxic cell injury, the progressive ultrastructural and morphologic sequence in necrotic cell death begins with ATP depletion causing failure of Na+/K+ pumps leading to early reversible cell swelling (B), rapid decrease in intracellular pH causing chromatin clumping (C), dilation and swelling of organelles like mitochondria and endoplasmic reticulum (D), culminating in irreversible plasma and organelle membrane rupture/damage with enzyme leakage (A). Hence, the sequence is (B), (C), (D), (A).