ST. LOUIS (AP) — Missouri transportation officials say hundreds of bridges across Missouri need repairs or replacing, but the state agency that oversees bridges doesn’t have the money for the work.

The Missouri Department of Transportation says it’s still paying off debt it assumed for bridge work a few years ago and new funding sources are needed to make the necessary repairs and replacements.

In the meantime, some bridges around Missouri have to be closed rather than risk carrying traffic. Three bridges have been shut down indefinitely since last year, and 641 of the department’s approximately 10,400 bridges are in critical condition.

MoDOT estimates it would cost about $820 million to repair or replace the 641 critical-condition bridges.