“We definitely do want to share this film with the Richmond community,” said Bova, 28.

The 4,000-foot-long tunnel, which runs from roughly Marshall Street between 18th and 19th streets to near Chimborazo Park, was built to move cargo from the port of Richmond to a rail yard near 17th Street. The decision to build a tunnel through the soft clay and limestone of Church Hill was ill-fated, and several workmen are believed to have died in cave-ins during the tunnel’s construction in the 1870s.

The infamous collapse occurred Oct. 2, 1925, during a renovation. The precise number of deaths is unknown, but experts believe at least four men were killed. The locomotive’s fireman made it out of the tunnel only to die a short while later. The body of Thomas Joseph Mason, the engineer, was recovered after a prolonged rescue effort. The bodies of two other laborers were never recovered.

The tunnel’s instability proved problematic during the recovery effort, and a 2006 exploration of the locomotive’s condition was halted amidfears that further excavation could create sinkholes that would damage buildings atop the hill.

One focus of the documentary will be on the way that the city’s dividing lines seemed to disappear in the face of catastrophe.