The National Building Research Institute (NBRI) has launched an investigation into the collapse of part of an earth embankment near the Kadigamuwa area for the second time of this month (October), which sent soil onto the railway track and disrupted train services. 

The NBRI warned that slopes destabilised by Cyclone Ditwah could become active again during rainfall, potentially leading to similar incidents in the future. The investigation will focus on identifying possible long-term solutions to mitigate such risks. Speaking to The Daily Morning, NBRI Senior Scientist Wasantha Senadheera said that further collapses could occur until the areas destabilised by Ditwah gradually stabilise over time. He said that the ongoing investigation would help identify measures to reduce the risk of similar incidents in the future. “We provided the designs to reconstruct the railway sections damaged during Ditwah, and they have been reconstructed. Following this, train services resumed. However, we cannot guarantee that these issues will not recur, as slopes destabilised by Ditwah could become active again. We have launched an investigation into this and will look into what measures can be taken in the future,” he said.

The investigation comes after part of an earth embankment near the Kadigamuwa Railway Station collapsed for the second time this month. A train that departed from Colombo Fort at 5.15 p.m. for Peradeniya on Wednesday (14) was halted at the Rambukkana Railway Station due to the obstruction. Earlier, on 5 October, two days after services resumed on the affected line, a morning office train struck a mound of debris between Ihala Kotte, Kadigamuwa and Gangoda, causing a derailment and major delays.

The restoration of the Upcountry Railway Line took nearly 10 months following extensive damage caused by Ditwah in November of last year (2025) and it was on 2 October that the regular passenger train services officially resumed.