Today SUS testers noted ITMY M0 top OSEM sensors railed (see Kissel/Barton alog entries below, 07:47 today). Concerned for the state of the ITMY monolithic fibers, we pulled viewport covers to inspect the quad. While the view of the TM was largely occulted by the AOS ACB, we could see evidence of fiber breakage on the floor in the form of glass shards. The ISI/SUS/HEPI underwent a major and sustained actuation. Investigations are underway to determine the cause. We will open BSC8 early next week to begin repair work. -Landry/Bland/Sadecki