There’s “Don’t Walk,” the sign some of us ignore most. There’s the lit-up hand and a light flashing “6” or “2,” a countdown showing pedestrians how many seconds are left to get out of a crosswalk.

Who doesn’t defy those?

A much-ignored sign with deadly consequences reads, “Please Don’t Drink and Drive.” It’s usually displayed with a smaller sign, “In Memory Of,” with the name of a drunken driver’s victim.

How many of us have had a couple beers and driven home? And how stupid and dangerous is that?

Every day, people ignore warnings about their safety.

Some cautionary advice is so common it becomes nearly invisible. What smoker bothers to read the surgeon general’s warning on a cigarette pack? “Smoking Causes Lung Cancer, Heart Disease, Emphysema, And May Complicate Pregnancy.”

One sign posted all over Yellowstone National Park is a drawing of a tourist being butted into the air by an American bison. “Warning,” it says. “These animals may appear tame but are wild, unpredictable and dangerous. DO NOT APPROACH BUFFALO.” Still you’ll frequently see a camera-toting visitor get out of a car to snap a close-up of the hulking beasts.

Since Monday, when a collapse at the rapidly melting Big Four Ice Caves killed one woman and injured five other people, much has been said about warning signs at one of Snohomish County’s most popular outdoor destinations.

Near the ice caves, there is the plaque installed about a year ago in memory of 11-year-old Grace Tam. The Marysville girl was killed July 31, 2010, when she was struck by an ice slab that broke from a melting cave. Grace hadn’t entered the caves and was standing nearly 20 feet away. Even so, the slab bounced and crushed her.

The plaque is a plea for caution: “The Tam family wants you to be aware that this is a beautiful but always changing environment. They hope that you enjoy the ice caves and Big Four Mountain only from a distance.”

A boulder at the site, with the U.S. Forest Service logo, warns that “People have died here,” and that “Your awareness and decisions can be the difference between life and death.”

Other signs there have graphics and words warning of collapsing snowfields, falling rock or ice, and an avalanche zone. And a big green Forest Service sign says: “Danger! Ice caves are unstable and will collapse. Do not enter or climb on top of the ice caves.”

It’s not surprising that some Herald readers have posted online comments critical of decisions made by Monday’s victims, who must have seen the signs. Ice cave visitors see multiple warnings, including the one from a grieving family. This summer’s heat has heightened the danger.

Graphic warnings should be enough to steer people away from very risky behavior. We can point fingers or question a person’s common sense, but most of us can also remember times when we have thrown caution out the window.

I have twice gone to see the ice caves. I was never so tempted that I went inside. Seeing video this week of an ice chunk falling from the caves, I now know we were too close for safety.

On one hike I had four kids with me, including two preteen boys. I’m lucky those kids didn’t run into a cave while we were eating lunch near the icy attraction.

Some cases of ignoring obvious danger go so far beyond tempting fate, they’re nothing short of crazy. On July 3, a 28-year-old Texas man died of an alligator attack after jumping into a bayou — a place posted with a sign saying, “No Swimming Alligator.” On July 4, a 22-year-old Maine man died after putting a firework on his head and lighting it.

Their loved ones are no doubt stunned, and left with as much sadness as those of someone killed crossing a street against a light. Ignore a warning, you’re at risk.

It’s dangerous and foolish to enter the Big Four Ice Caves, but it’s also understandable.

People are curious. It’s a unique and fascinating place we wouldn’t otherwise see. I can imagine thinking, “I’ll just dash in for a second. What are the chances ice will fall on me?”

Anyone taking that chance could easily be wrong. We saw that this week. Yes, people were warned — but that makes me no less sorry that they were lost or hurt.

Julie Muhlstein: 425-339-3460; jmuhlstein@heraldnet.com.