A bridge under construction in a mountainous region of central Colombia has collapsed, throwing 10 workers about 900 feet to their deaths.

The victims had been doing drainage work on Monday on the Chirijara bridge, a 1,500-foot-long structure over a gorge about an hour’s drive from Villavicencio, on the highway to the capital, Bogotá.

Nine of those who fell died immediately, and the 10th died of his injuries after being taken to a hospital.