Firefighters in Houston are still trying to determine if any lives were lost in a massive scaffolding collapse outside of an under-construction building downtown.

What is known is that at least six workers were injured in the metal heap. No passers-by were hurt.

Houston's Office of Emergency Management says the accident occurred near the corner of Crawford and Preston streets, which is not far from Minute Maid Park. Residents are being urged to avoid the area so that first responders may attend to the accident.

Video from the scene displays piles of metal outside of the seven-story building. The collapsed scaffolding covers about one city block in downtown Houston.