I have a lot of relatives who live in Montreal, so my family and I visit every once in a while. About eight years ago, we were driving through the city in the winter, probably on our way back to Toronto. The roads were snowy and icy, but we had snow tires so we were pretty sure it was safe to drive around.
Just as we were driving under a bridge, though, a truck going over-top dislodged some ice and snow. BAM! It hit our windshield, and the glass spidered with cracks.
I've heard of times where people get hurt in similar situations because they swerve off the road, or are hit by other cars around them. Luckily for us, my dad's a pretty mellow guy. He slowed slightly, rolled down the window, poked his head out to see where he was driving, and pulled over to safety.
"Huh," my mom said, "that was surprising."