https://thenextweb.com/apple/2018/06/18/apple-share-location-911/

Apple today announced iOS 12 would have a new feature which enables US-based users to automatically share their location with emergency services when they call 911. This new location-sharing would allow 911 centers to find callers location faster and with much greater accuracy than they can under the current system — and finally brings US users up to speed with those in Europe.

As Apple itself astutely observed, most 911 calls made these days come from mobile devices. To redress the fact that most 911 call centers have trouble locating such calls, Apple is collaborating with RapidSOS, an emergency tech company which adds a “data pipeline” through which the company can feed its Hybridized Emergency Location (HELO) data to emergency services.