Note: This information was taken from TSR's original AD&D adventure, the Temple of Elemental Evil.
For the players: For at least 100 feet of its length, this 20 ' wide corridor is covered with bones. Skeletons of humans and humanoids are mixed in a terrible jumble. Many skulls and loose bones seem gnawed. The complete skeletons, though, still wear sundered armor, dented caps, or sprawl by broken shields. Bent and broken weapons likewise testify to a great melee having taken place here; a hundred, two, perhaps more... all met death here. Further progress along the corridor requires carefully picking a path between these grim remains of the Temple hordes. Nothing of value is discernable.

For the DM: If the party enters the corridor area shaded on the map, they spring a trap. When they get to the central area (just south of the secret door to area 131), the following events occur:

a. Ten human skeletons spring up from the west end of the shaded area, charging east to the attack;

b. Six gnoll skeletons spring up at the east end of the shaded area, moving west to surround the intruders.

In addition, the two ogres (area 124) watching for trouble join the fray if the intruders (PCs) are nearly slain, or if the party retreats into the southern 20' wide corridor leading to their door. If the latter, the ogres probably (75%) gain 1-4 surprise segments unless their door is being carefully watched.

Skeletons, human (10): AC 7, MV 12",
HD 1, hp 8, 6, 5, 5, 5, 5, 4, 4, 4, 3;
#AT 1, D 1-6; XP 22, 20, 19 (x4), 18 (x3), 17

Skeletons, gnoll (6): AC 7, MV 9",
HD 2, hp 12, 11, 10, 9, 8, 7; #AT 1, D 2-7; XP 52