Two people have been seriously injured in a Sydney building collapse. NewsWire / Richard DobsonTwo people have been seriously injured in a Sydney building collapse. Part of a building gave way beside a Shell service station on Wattle St, Ultimo about 11am on Monday. Two people are in a serious condition after a wall and partial building collapse in Sydney’s inner city sent debris crashing onto vehicles near a service station in Ultimo. Camera Icon Drone footage shows the extent of the building and wall collapse on Wattle Street in Ultimo, where two people were seriously injured.