Our neighborhood in Ballard is sinking who to contact?

We had our foundation repaired last year and stabilized down to 15 ft of bed rock, confirmed with load tests and geo tech inspection by City of Seattle. Over the past couple of months I have noticed new cracks, but dismissed them. Now I learned 2 of my neighbors within a block radius have sinking foundations, houses have been stable for 100 years. They have sunk over 2″ in less than a few months. I am having my foundation company out next week to investigate how much our house has shifted again. Who can I contact from Seattle about this? Worried that this is a large scale issue. Thanks!