This morning Ed asked me to look at some trend plots he had just generated. Clearly noticeable was a sharp rise in the humidity and a drop in the flow rates for the heads. I checked the crystal chiller and its water level was below minimum and the controller displayed an error informing of such. Attached is a picture of the burst hose attached to the head 3 water cooling circuit. This is the same connection that failed ~2-1/2 years ago. I do not recall if it has been adjusted since that time. Although care is/was taken to prevent twisting of the hose when the fitting is tightened, it is highly likely that there was a small twist in the hose that exerted a small shear resulting in the tear seen in the picture. Also attached is a picture of the 4f lens for head 4, clearly showing some water droplets on it. Apart from the obvious step of replacing the hose, the turbine flow sensor for head 4 will also be replaced. The laser will take the better part of a day to dry out - to be on the safe side. All optical surfaces and the fibre bundle tips will need to be inspected for cleanliness before any operation of the high power oscillator is contemplated.