It has been 30 years since Connecticut and the nation were shocked by the collapse of a portion of the Mianus River Bridge on Interstate 95 in Greenwich.

Three people were killed and three others seriously injured on June 28, 1983, when their vehicles plunged 70 feet into the river below. Fortunately, the collapse occurred at 1:30 a.m., or the death and injury toll would doubtless have been much higher.

August 1 will mark the sixth anniversary of the deadly rush-hour collapse of the I-35W Mississippi River Bridge in Minneapolis that took the lives of 13 people and injured 145.

After both of those tragedies, the state of Connecticut -- under the leadership of Gov. William O'Neill in 1983 and Gov. M. Jodi Rell in 2007 -- appropriately made a greater investment in bridge inspection and maintenance.

Predictably, with the passage of time, the focus on ensuring the safety of the state's bridges is no longer as sharp -- or as high on the priority list -- as it was in the immediate aftermath of those bridge collapses.

The reality, though, is Connecticut's bridges -- like bridges all across the country -- are aging, and many of them are deemed "structurally deficient" both by watchdog groups and highway officials.

In fact, roughly 10 percent of the state's more than 4,000 bridges with spans of 20 feet or more are on that list, which places Connecticut just below the middle of the pack nationally in terms of bridge safety.

It is sobering to realize the average age of bridges in the state is over 50 and the number of bridges on the "structurally deficient" list has increased by more than a dozen since 2011.

Nearly every town in the area has one or more bridges bearing that designation, including Ridgefield and Newtown, which have one and three bridges, respectively, considered among those in the worst condition. The Ridgefield bridge is on Route 7, near its intersection with Route 102, while all three Newtown bridges are on I-84.

To be fair, "structurally deficient" does not mean the bridges are unsafe today. It means maintenance and repairs are required in the near future to ensure their safety.

And the good news is most municipalities have ongoing programs for bridge maintenance and repairs.

In New Milford, for example, there are eight bridges on the "structurally deficient" list, and every one of them has been targeted for refurbishment.

According to New Milford Public Works Director Mike Zarba, all eight bridges have either undergone repairs, are currently being worked on, or are in the design or planning stages.

Of course, as Zarba points out, bridge maintenance is a never-ending process, and as work is completed on a list of priority bridges, a new list begins to grow.

In that context, the bad news is, in these economically challenging times, neither the state nor the federal government is providing sufficient funding for inspection, maintenance and repair of bridges.

That needs to change.

Hopefully, the 30th anniversary of the Mianus River Bridge collapse, the upcoming sixth anniversary of the Mississippi River Bridge disaster and the partial bridge collapse in Washington state in May will serve as a wakeup call to elected officials in Hartford, in Washington, D.C., and across the country.

A major commitment is needed for infrastructure projects -- locally, statewide and nationally.

We shouldn't have to wait for the next tragedy for that commitment to be made.