"Cautious Californian" writes in with:
Why is it that there are so few civilian casualties during many hero-vs.-villain encounters that turn violent? I do my best to run away & rob another day, but some villains seem trigger-happy. Shouldn't that be incredibly dangerous?
This was true back in the 60's and early 70's. What happened after the first few attacks was that strategic planners got involved. They reached out to the people who'd devised London's defenses during the Blitz, to the Israelis, to the Army Corps of Engineers, and so forth. A lot of this expertise filtered into FEMA (the Federal Emergency Management Agency) when it was signed into existence in 1979.
Everyone's conclusion fell into a few different buckets.
First, that all rebuilding should include hardening of the buildings that were damaged. This meant emergency shelters, accessible stairwells, structural reinforcement, and the like. Every reconstructed building would include food, water, electricity, and first aid kits. Every shelter would have a signaling system to contact the fire department, police, and so forth.
Second, that supers could rebuild damaged infrastructure far faster than conventional contractors, given similar levels of competence. This led to the funding of super-teams like the Metahuman Task Force, at least in states that were willing to throw around their tax-driven revenues. Conveniently, most states where a lot of these fights happen are also ones with a lot of tax money to spend, so there you are. Nobody cares about throwing down in Kansas.
Third, that nothing could really stop a reasonably powerful super except another powerful super. This has led to the current schizophrenic legal views on supers in the United States.
If you're a supervillain, you may not actually appreciate the outcome of all these steps. You haven't actually worked in an office building or a skyscraper. Here's what it's like.
When word comes out that a villain is nearby, there's a klaxon broadcast through the building. The building security service comes on over a PA system, asking people to descend the stairs. The elevators get shut down, with the exception of those needed to evacuate disabled people. The office workers mill around in the elevator room, checking their mobile phones, gossiping, and being impatient.
If the building itself does come under attack, security tells them to continue down the stairs and into the shelter. Head counts are taken. Someone in security calls the police dispatcher, who ignores them in favor of the more important calls coming in talking about the battle. Once the danger passes, everyone is escorted outside and goes home for the day while the building is inspected for structural damage.
So yeah, the short version is that while a single villain attack can cause millions in property damage and lost productivity, there's a lot of stuff in place to keep the civilians physically safe.