scope:

Abstract:

During weekend work conducted February 3 and 4, 2007, contract workers removed the existing B1201 roof material, which uncovered an old drain (drain 1). This drain 1 had been abandoned in place, the drain pipe had been cut, and vertical section removed below the roof deck. During the same activity the roofers broke the PVC bowl of a nearby active drain (drain 2). The workers, believing that drain 1 was viable, proceeded to unblock the drain pipe and finished the drain location to the completed roof. As part of the same operation, the workers did not repair the drain 2 damage, instead they covered over this drain. Over one (1) inch of rain fell at the Stennis Space Center during the night of February 12th and the morning of the 13th. Rain entered B1201 through drain 1; the rain fell on and damaged several pieces of IT equipment. In a separate location another drain pipe connection to an internal drain also failed, allowing water to flood an adjacent hallway. This incident was classified a Type B Mishap according to NPR 8621.1B -- 'NASA Procedural Requirements for Mishap Reporting, Investigation, and Recordkeeping'.

The proximate causes leading to the mishap are listed below.

1. The abandoned drain (drain 1) opened at roof level.

2. The opened, abandoned drain (drain 1) pipe ended above IT equipment.