 On 20 February 1911 when the express was approaching Paekakariki from the south, a large boulder dislodged from above on the Paekakariki Escarpment rolled down onto a second class carriage, killing Miss Alice Power (23y) from Greymouth who was travelling with two friends.By 1914 the travel time was 9 hours 4 minutes with track improvements in 1914 which allowed the speed limit in some places to be raised to 73 km/h and the more powerful A class locomotives was introduced about 1917-18.By 1925, it was down to 7 hours 31 minutes, partly due to the new AB class locomotives, and a further improvement in 1939 was 7 hours 17 minutes when the Tawa Flat Deviation eliminated the torturous, winding route via Johnsonville into Wellington and the K class began operating the expresses.