Part of the Third Street Tunnel remains closed Wednesday as crews work to fix a water main break.

       The road is closed in both directions between New York and Massachusetts avenues NW. It is not known when it will reopen, but officials have said it could be days before the highway will fully connect with downtown Washington.

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       Part of the tunnel has been closed since Monday, causing backups in the morning and evening rush hours. Northbound and southbound lanes in the tunnel, which is part of Interstate 395, reopened Tuesday south of Massachusetts Avenue NW.

       The water intrusion stemmed from a broken eight-inch water main behind an auxiliary wall that flooded the road and left hundreds of nearby residents without water for hours. Crews on Tuesday were still pinning down the exact location of the leak.

       D.C. officials said southbound lanes sustained significantly more damage because they are at a lower elevation and had more standing water. On Tuesday, crews were finishing an assessment of damage. Then they were expected to begin making repairs.