During World War II several cars were lost. 14199 (P stock DM) was destroyed at Neasden on 27 September 1940, 13036, 14042, 14049 (all O stock DM), 13229, 14229 (all P Stock DM), 014080 (O stock trailer) at Moorgate station on 29 December 1941, and 14263 (P stock DM) at Baker Street on 10 May 1941. To make up for the number of 'D' end DMs (14xxx) cars destroyed, three 'D' end trailer cars were rebuilt into DMs. These were 014270-014272 which were renumbered 14270-14272 when converted. DM 14233 was damaged during bombing and one end of the car was destroyed. This was repaired using an end of Q38 Stock trailer 013167, which had also been badly damaged. The rebuilt car entered service renumbered 14233 in 1941; it became 54233 in 1963.
