Work crews broke through the stone arch of the 1852 Wabash Creek Tunnel on Thursday, but appeared to shift gears slightly after finding a network of buried asbestos cable duct pipes running parallel to the curb.

The workers were excavating to replace the 166-year-old subterranean bridge when they came upon the asbestos conduit. Each of the pipes measures about 6 inches in diameter and appear to carry telephone cable along Broad Street.

A representative from Verizon was summoned along with an asbestos abatement unit. A truck from Coventry Environmental of Spring City, Pennsylvania, arrived at the project site before noon and workers began to set up a tent shield to begin removal and disposal of the hazardous material.

The $2.1 million Pennsylvania Department of Transportation project is drawing a legion of followers as it uncovers, for the first time, the hidden Wabash Creek where it crosses beneath Broad Street.