Another railway disaster, and in its day New Zealand's worst, occurred in the King Country on 5 July 1923. The Main Trunk express from Auckland to Wellington crashed into a huge slip at Ongarue, near Taumarunui, and was wrecked. Fourteen people were killed and 30 seriously injured. It had been an ill-fated journey from the outset. As is often the case in winter, heavy weather had been drenching most of the inland area of the North Island for days. Landslides and rail blockages had been reported from many points, and the outlook was so unpromising that the departure of the express from Auckland had been delayed for four hours. Finally it was decided that a start could be made on the 426–mile night journey. After leaving the Waikato Plains behind, the train edged its way gingerly round minor slips and obstructions, and then plunged heavily into a veritable landslide at Ongarue.

In October 1940 the Limited express, northbound from Wellington to Auckland, encountered trouble at 8.15 a.m. on the final stages of its journey when, without warning, the engine and tender jumped the rails. Fortunately the following carriages did not follow suit. In this case appearances outdid reality to an alarming degree. The permanent way was a shambles, but no deaths occurred among the full complement of passengers. Ten were seriously injured, but the only fatalities were the engine driver and fireman, who were killed when the locomotive capsized. B.J.F. and R.J.