(4:15 p.m.) — A water main break is causing a major traffic disruption this afternoon at the busy intersection of Blue Hill Avenue and Morton Street. Workers are on the scene now making repairs to an water main line that was ruptured earlier in the afternoon— causing a flood and a huge hole in the southbound side of Blue Hill Ave.

The Boston Transportation Department has issued an advisory warning drivers that "Morton Street outbound toward Lower Mills in Dorchester is closed at this time from Harvard Street to Blue Hill Avenue due to a water main break." BTD said it expects one lane to re-open before 5 p.m. Inbound traffic on both Morton Street and Blue Hill Avenue remains open.

Colin Donnelly, a spokesman for Boston Water and Sewer Commission, said the damage was caused by subcontractors for National Grid who were working to repair an electrical line in a trench when the accident occurred. They will be responsible for making the repairs under the supervision of a BWSC inspector, Donneely said.

"It's a significant hole," said Donnelly, who said that traffic was restricted to one lane on the busy thoroughfare's southbound route at this hour.

The main itself was shut down for a time, but water has been restored at this hour, Donnelly said.