To update my last post, the pending tree removal requests are now on the city website here
Besides, removals, Marc has also posted the list of open pruning requests. This will be useful, because unlike removals, which have the metal tags, trees on this list are not marked in any way. But now if you see a tree you are worried about, you can see if it’s already made the pruning request list. (That’s not to say it might not have gotten worse since first being reported.)
Keep in mind that it’s not just dead trees that may be hazardous. A tree could have a full canopy, but a structural defect, like this crack developing in an ash tree (which got removed last year as a result). If you spot anything like this, report it! More eyes are better than fewer.