[8] Agalawatte, a town within Kalutara District, reported 47 deaths and 62 people missing as of 29 May, with many areas made inaccessible by landslides.
The areas that usually receive the heaviest rain are the south and west of the country, including Kalutara, Ratnapura, and Colombo.
The monsoon was anticipated to arrive after 14 May, but owing to below-normal water levels in the region, it was initially not expected to cause severe flooding.
[7] On 27 May, an area of convective thunderstorms in the Bay of Bengal started to converge, moving to the northeast and becoming Cyclone Mora on 28 May.
By the evening of 25 May, the National Building Research Organisation (NBRO) of Sri Lanka had issued a "Level 3 Red Alert" landslide warning for the districts of Ratnapura, Kegalle, Galle, Kalutara, Matara, Hambantota and Nuwara Eliya.
[15] The Sri Lanka Armed Forces initially deployed nearly 10,000 personnel and equipment for relief, help and rescue operations.
[17][18][19] The Sri Lanka Navy deployed over 110 search-and-rescue teams comprising 776 naval personnel along with 116 relief boats.
[21] During search and rescue operations a Sri Lanka Air Force Mil Mi-17E crashed over the Baddegama area, but no one aboard the chopper was injured.