The 9 April 2026 landslide at Lamarain in Papua New Guinea

Ten people were killed in a large landslide in Papua New Guinea triggered by heavy rainfall associated with Tropical Cyclone Maila.

On 9 April 2026, a large landslide occurred at Lamarain in the Inland Baining LLG of Gazelle District in Papua New Guinea. The landslide was triggered by heavy rainfall associated with the passage of Tropical Cyclone Maila.

Media reports indicate that ten people were killed by the landslide and that a further 18 people were injured. Baining is located at [-4.2548, 151.7811], so I assume that this is the general area.

Gaining information about landslides in the remote areas of Papua New Guinea is very challenging – the terrain is rugged and there is a high level of civil turmoil. But the best source of information is on the Facebook page of NBC East Britain, which has posted a helicopter video of the aftermath. This is a still from that video:-

There are several interesting aspects of this landslide. First, the failure appears to have initiated high on the hillslope in an area that has a mix of forestry and cleared areas. The source appear to be quite large and deep-seated. This has transitioned into a disrupted debris slide / avalanche with a substantial amount of entrainment.

Note also the multiple other landslides in that area, all fresh, suggesting that the intense rainfall was sufficient to drive widespread failures. It is interesting to note though that is event did not involve multiple shallow landslides that combined to create a channelised debris flow.

The Post Courier reports that the Lamerain landslide occurred in two phases, the first at 6 am on 9 April 2026 and the second 24 hours later. However, other reports suggest that it occurred on 12 April 2026, underlying the challenges of properly understanding landslides in Papua New Guinea.

Text © 2026. The authors. CC BY-NC-ND 3.0
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