Geologists are currently mapping recently discovered tunnels under Rome. The dark, twisting underground roads and passageways are a threat to the integrity of the streets and buildings above them. Teams of geoscientists hope to prevent modern structures from sinking into the voids below them.

Incidents of collapsing structures and streets started being reported in 2011. At the time, the tally of such events totaled 44. In 2012, the number rose to 77 and then it once again increased to 83 in 2013. In order to prevent further collapse into the tunnels under Rome, researchers from George Mason University and the Center for Speleoarchaeological Research mapped at-risk areas. Kysar Mattietti, a geoscientist, stresses the importance of mapping the tunnels as citizens have taken it upon themselves to patch the quarry systems. The common method of doing such was sticking a plastic bag filled with cement in the holes effectively only filling the voids near the surface.

Though early Romans knew to keep the tunnels narrow in order to support the city above, there were factors that eventually would threaten the integrity of the underground system. Mother Nature and the human race, over time, weathered and expanded the tunnels under Rome making them a hazard to modern structures today.

The tunnels under Rome became an open secret for its citizens. They began to use them as catacombs, sewer systems and even bomb shelters. The younger generation, however, are less aware of the geological time bomb beneath their city.

Geoloscientists used 3D scanning to find hidden weaknesses in the underground passageways. Once they can be sure an area is safe, researchers enter the tunnels and map the intricate system by hand.

Cracks, collapsed ceilings and voids create hazards for the citizens above ground. City officials sealed off potentially dangerous sites and poured mortar into the tunnels to fill voids.