There is provided mitigation of disconnect events in a vectoring based digital subscriber line, DSL, system. A method performed by a digital subscriber line access multiplexer,DSLAM, comprises detecting a loss of signal or disconnect event of a line in a vectored group of DSL lines,the loss of signal or disconnect event causing a negative impact on the DSL system. The method further comprises detecting a change in at least one downstream, DS, crosstalk coefficient of at least one line in said vectored group of DSL lines. The method further comprises determining a magnitude of said change. The method further comprises determining where the loss of signal or disconnect event has occurred by processing precoding coefficients of the vectored group of DSL lines. The method further comprises determining,on basis of the determined magnitude and where the loss of signal or disconnect event has occurred, an action to be performed by the DSLAM so as to mitigate for said negative impact.