The three-needle pine trees, scattered along the route, were 10-16 metres tall with trunk diameters ranging from 15 to 70 cm.
Most were growing precariously on slopes above the road and were at risk of falling onto the pass, while some had already died.
Prenn Pass stretches 7.27 km along National Highway 20 and is a major route connecting Dalat with HCM City.
Prolonged heavy rain in recent days has triggered landslides on slopes above and below the road, posing risks to motorists.
Soil and three large rocks fell from a slope tens of metres high onto the road on September 19. Drivers spotted the landslide and stopped in time, preventing casualties or property damage.
On September 22, Lam Dong authorities declared an emergency over the landslide and ordered urgent stabilisation work at the site on National Highway 20 in Xuan Huong-Dalat Ward.
The emergency project is estimated to cost nearly VND 16 billion (USD 611,000).
