Representative micrographs of H&E-stained lung sections are shown from young (A, C, E, and G) and aged (B, D, F, and H) animals at 6 h after sham injury (A and B), 6 h after burn injury (C and D), 24 h after sham injury (E and F), and 24 h after burn injury (G and H). All images are at 100× original magnification.