A Civil crew was engaged in excavation for 30” via GRE piping. While digging the trench from 2.4m to 2.9 m depth, a part of the trench wall collapsed and fell on the ground worker who was using the jack hammer. Some soil fell on the other two crew members who were also working inside the trench. One of them was diagnosed with Pelvic fracture and other was diagnosed with minor contusion on right knee.