His feat puts the structure of the tunnels at risk. I don’t know specifically how much damage this aerobatic plane could cause when it strikes the lighting, ventilation, and concrete of that structure. I doubt that his liability insurance covers this type of flying. If the structure is a public utility, then it’s the tax payers who are forced to pay. Unless, of course, the tunnel has insurance that covers this sort of risk…or that an insurer would even offer this type of coverage.