The collapse caused a large section of cinderblock wall to give way at about noon at an installation and maintenance facility at 160 Pamrapo Avenue that also houses a work center. One side of the building fell in.
Three people were inside at the time, and all were treated for minor injuries. Verizon officials say most workers were out on jobs when the collapse occurred.
Verizon officials say everyone has been accounted for after rescue workers went through the building.
About a dozen trucks inside the building were damaged beyond repair, and some of the employees' personal cars were crushed.
PSE & G and United Water crews responded to the scene to repair a water main leak caused by the collapse.