The blast happened at around 2 p.m. on March 31, the report says. Employees reported the explosion caused a corner of the Curtis Bay Medical Waste Services building to blow out.
According to the report, the front and back facades of the building were taken out and a nearby car was smashed by falling concrete. A witness also told NBC12 they saw downed power lines and people running from the building.
At least four people were inside the building, with three being sent to the hospital. There were no deaths on the scene, the report says.
The Petersburg Fire Department declared the building not secure enough for anyone to go inside, and Columbia Gas crews monitored the building. According to the report, there was no indication that a gas leak caused the explosion.
The cause of the explosion was still under investigation at the time of the report.