? A ruptured gas line forced the evacuation of businesses on Jefferson Street in Stamford Tuesday morning.

Investigators say a crew installing sewers hit the 2-inch gas line at around 10 a.m. About 100 people working in nearby businesses were evacuated, but have since returned to their jobs. Part of Jefferson Street was also closed off.

One of the businesses evacuated due to the leak was the nearby Metro-North rail yard. However, train service was not affected.

Fire officials say the gas line was marked. The crew?s project manager is looking into circumstances surrounding the break.