There were scientists who were curious about this as well. They actually found live Twitter data was quite helpful in tracking earthquakes. This is one of the big reasons I believe in keeping social media data open.
https://www.research-collection.ethz.ch/bitstream/handle/20.500.11850/364555/2/5364-9174-1-PB.pdf
The comment text itself stays but the user says "deleted". You need to use an external tool to delete the post content. Normally I wouldn't nuke my comment history, but the API changes may make such tools stop working soon.