What happened to comet 73P/Schwassmann-Wachmann 3?

Comet 73P/Schwassmann-Wachmann 3 was observed in September-October 1995 with the Nancay radio telescope as part of our program of observations of potential targets for the ROSETTA International Mission. We observed an increase of the OH production rate which reached a level more than one order of magnitude larger than expected from the visual observations at the previous returns. Following this alert, observations revealed a similar increase of the total visual magnitudes of the comet; a split nucleus was observed in December. We present and discuss the radio observations. It is suggested that the enhanced activity of the comet is related to the disruption of its nucleus.