This has been all over the news this week so I am sure many people are aware but a massive sized sinkhole opened up and swallowed the entire back end of a home in Hudson. Luckily the homeowner was not home and no one was injured. Unfortunately, the homeowner is a widow who was living alone in this house and now the home has been condemned by the County for the time being, leaving her without anywhere to live. Supposedly some family in the area is helping out so sounds like she is being taken care of. The interesting part of the story is that this home was apparently in the process of being tested for sinkhole activity when the collapse occurred.
This is something that can happen relatively frequently. Either testing for sinkhole via a standard penetration boring or even drilling injection points in the ground to begin a grouting repair can disturb unstable soils causing them to collapse. If this appears to be a concern, most engineers will recommend contingency underpins. This means they will underpin a home prior to performing the work to ensure that if a collapse does occur, the home will be stabilized and still standing. If you have concerns with unstable soils near the surface of your property, this may be something you ask your insurance company and their engineers about.
The other interesting note from this issue is that the neighboring property was grouted years prior to this collapse. This can sow how grout can really be confined to a small area and is unlikely to remediate unstable soils that were even just feel away from the home.