State Sen. Bob Duff (D-Norwalk) says the state is aware of problems with an antiquated Metro-North swing bridge and is working toward a solution.

Connecticut recently applied for $350 million in federal funding to replace the 118-year-old bridge.

The bridge in South Norwalk failed to close during maintenance and brought Metro-North service to a halt, drastically lengthening commutes Thursday morning. Service has since resumed.

Trains also stopped in their tracks in October 2011 and again last June when the bridge similarly stuck.

Transportation officials say the department has spent more than $1.5 million in recent years to improve the bridge's reliability. They also say a replacement bridge design is in the works while they try to get federal funding for the project.

Authorities say they regularly do work on the 118-year-old bridge to keep it functioning properly, and that repair work is just a temporary solution.

Even if the state secures the desired funding, officials note it will be about 10 years before a new bridge's completion.