As pointed out by taejo the San Francisco Airport Commission. Also I haven't tried to purchase terrorism insurance recently. The last time I did that was in 2005, and I bought it from Standard. It was for a VIP and travelling party, so on a smaller scale, but they'll insure anything to anyone for which there are statistics and money. 1-in-30,000,000 for an individual, it shouldn't be too hard to scale that to a airliner or even a whole airport.
Would it have stopped 9/11? Did the TSA? Did anything else we tried? Nope. Because we didn't know about it until it happened. What it would have done is made sure that the cost of the cleanup and re-build didn't turn into a decade+ long charlie-foxtrot situation, and would have incentivized the airports to not let it happen again, instead of just putting on a show.
Would it have stopped 9/11? Did the TSA? Did anything else we tried? Nope. Because we didn't know about it until it happened. What it would have done is made sure that the cost of the cleanup and re-build didn't turn into a decade+ long charlie-foxtrot situation, and would have incentivized the airports to not let it happen again, instead of just putting on a show.