By Thanh Tuan  April 15, 2018 | 02:23 pm GMT+7 Victims are rescued from the ground in Lao Cai Province on Saturday. Photo by VnExpress/Thanh Tuan The workers were building a wall designed to protect people from the type of disaster that killed them. Three people were killed and another was injured when a landslide hit a construction site in the northwest of Vietnam on Saturday. The four construction workers from Lao Cai Province were building a wall in Duyen Hai District that was intended to protect local houses from landslides. Over 200 local police and rescue workers were dispatched to rescue the crew. It took the emergency services an hour to dig out two people, one of whom died on the way to hospital. The two other victims were found dead four hours later. Local authorities have compensated the families of the dead victims VND2 million ($89) each, and offered VND1 million ($44) to the injured worker. Officials said the construction work had not been authorized. Landslides are a common occurence in Vietnam’s mountainous regions, especially during the monsoon season. Last October, heavy downpours caused a landslide that killed 18 people in the northern province of Hoa Binh.