On 30 December 2004, "Kanimbla" sailed as part of Operation Sumatra Assist, the Australian contribution to relief efforts following the 2004 Indian Ocean earthquake and tsunami. The ship's involvement ended on 26 March 2005, and she sailed to Singapore, but was redeployed three days later after a new earthquake off the Sumatran coast. On 2 April, a Sea King helicopter operating from "Kanimbla" crashed on the island of Nias, killing nine of the eleven personnel aboard; the single deadliest incident in the Australian Defence Force since 1996. Operations did not conclude until 13 April.