St. Louis firefighters battled three vacant structure fires in the same block of St. Louis Avenue in 24 hours.
Fire investigators are working to determine if the fires are related, according to KMOV.
The first fire broke out around 8 p.m. Friday in a vacant building in the 3900 block of St. Louis Avenue.
The second -- at 8 a.m. involved a vacant two-story house.
The latest fire was just 12 hours later at 7 p.m. in a vacant two-story commercial building.
Fire officials warned that all structures may collapse.
