The chief culprit is suspected to be poor drainage at a disused military firing range on top of the hill. The Shihlin District Prosecutor's Office is carrying out an investigation, and has not ruled out other possible causes, such as illegal logging, or that the drainage system for the whole area is inadequate.
山坡上方的軍方廢棄靶場排水系統不良，被懷疑是禍首，士林地檢署檢察官目前正在調查當中，同時不排除是居民在山坡地濫墾或是全區排水系統不良等原因造成。