Of all the street trees that came down that I saw, only 1 (the last pic) was a healthy tree that simply uprooted. Every single other street fall was badly rotted, in some cases by more than 90%. Trees like this inevitably come down, and it may not be in anything worse than an ordinary thunderstorm. If you have large trees in front of your home, pester the city to have them checked out, or demand permission to check yourself. (NYC does not allow people to do anything to street trees- including pruning or putting up signs. You can be allowed to prune street trees if you take a class in pruning and get a certificate for it.) Also, on your own property, use good judgment in your plantings. That blue spruce was on private property...once they get tall, they are very prone to uprooting in storms. They are OK as part of a forest in the Rockies, but they are out of their element as a single specimen on a lawn or in front of a house.