Due to heavy rains since 16 March 2018 at 17:00hrs on the mountain, landslides hit the riverbed around Sentani causing flash floods with logs and sedimentary rocks that were channeled to the downstream. Nine villages in Sentani sub-district, Jayapura regency were affected. According to Sutopo Purwo Nugroho, the spoke person from the National Agency for Disaster Countermeasure or Badan Nasional Penganggulangan Bencana (BNPB), during eight hours of rains, the rainfall reached its extreme condition up to 235.1 mm/hour. There is an indication that landslide occurred in Cyclop Mountain which is the upstream area. Cyclop mountain is one of the conservation mountains in Papua.
According to the information provided by BNPB and Meteorology, Climatology and Geophysical Agency that was compiled and circulated via e-mail by UNOCHA; as well as information from PMI, on Sunday, 17 March 2019, the flash flood affected nine sub districts in Jayapura regency, and four sub-districts in Jayapura city. Furthermore, according to the report:
Around 11,725 households are affected where among those 77 people died, 43 people missing, 74 people injured, and 4,226 people displaced, who are scattered around various sites and evacuated to 6 different evacuation points.
Approximately 350 houses were damaged; while the water also inundated six areas, including 1,450 houses in Gajah Mada, 1,000 in Jayapura, Kemiri dan Sentani, 200 district offices, and 200 in Doyo.
Water resource at Cyclop Mountain contaminated by mud and logs from the landslide.
The number of casualties is estimated to increase as the evacuation process is still continuing and not all the affected areas have been reached by the joint Search and Rescue (SAR) team, as they are covered by trees, rocks, muds and other flash floods materials.
A joint emergency response team from District Disaster Management Authority or Badan Penganggulangan Bencana Daerah (BPBD) BPBD together with the military, police, the National Search and Rescue Agency (Basarnas), local government office, Ministry of Social Welfare Volunteers (Tagana), Indonesian Red Cross (PMI), volunteers and the community are providing emergency response support such as evacuation, field kitchen, and emergency posts to the affected people. Local government has mobilized heavy equipment such as four excavators, four wheel-loaders, 10 dump trucks to clean up debris along Jayapura-SentaniKemiri main road.
Based on initial information from secondary sources as well as from PMI teams on the ground, immediate needs include evacuation and management of clean water, blanket, mattresses, medicines, food items, and hygiene kits.