Chord observations of radiation from oxygen impurity ions (O III, O IV and O V) in the LT-3 hydrogen plasma have been made simultaneously through a number of optical ports. These showed a spatially structured entry of oxygen into the plasma just before the disruption and, at the disruption, an expansion of the central plasma into the outer regions with velocities of 3–8 km · s−1. The plasma column appeared to be kinked with a stationary modal structure of m = n= 1 on which were superimposed a moving central m = 1 perturbation and, at larger radii, moving perturbations with m > 1.