Old bridges can kill.

Washingtonians got a dramatic reminder of that fact Wednesday when a 40-year-old span in Minneapolis collapsed during rush hour, plunging dozens of cars into the Mississippi River.

It’s a chilling reminder that we should be paying close attention to our own infrastructure. Two state bridges – the Alaskan Way Viaduct and the Highway 520 bridge over Lake Washington – carry heavy traffic and are perilously vulnerable to collapse.

Others are at least worrisome. In Seattle, for example, both the Interstate 5 bridge over the Ship Canal and the 75-year-old Aurora Bridge have the same steel-truss construction as the I-35 bridge in Minneapolis.

Of the state’s more than 7,000 bridges, roughly 5 percent are rated structurally deficient in some way. Washington’s highway engineers think nearly all of them are safe, but Minnesota’s highway engineers thought the I-35 span was safe, too – it was frequently inspected.

Close to home, Tacoma’s Murray Morgan Bridge is severely corroded but still open to low-weight vehicles. The state Department of Transportation wants to tear it down; the city wants to save it. That issue needs to be back on the front burner.

Unfortunately, the DOT is short of money for fixing bridges. One reason is that a single project – replacement of the eastern half of the Hood Canal Bridge – has turned into a money pit. It is sucking up $204 million more than estimated – $476 million instead of $272 million.

Replacing and shoring up bridges and other critical infrastructures has never been an “issue du jour” in Olympia; as a political cause, it’s not nearly as compelling as sex offenders, the WASL or whatever.

To their credit, lawmakers made a real dent in the problem when they approved a controversial gas tax increase in 2005; that financed scores of highway safety projects around the state, including bridge improvements. But there’s not remotely enough money in the DOT’s piggy bank to cover the $4 billion cost of replacing the Highway 520 bridge, and state and Seattle leaders are still dithering about whether to replace the Alaskan Way Viaduct with a tunnel or another viaduct.

There’s a message in that deadly jumble of concrete and steel in Minneapolis: It can happen here. The cost of letting old infrastructure crumble can be far greater than the cost of fixing it, in human life as well as dollars.