At least in my area, King County area, a call of severe chest pain would immediately get units rolling code (lights+sirens) for CHEST PAIN. Pulse point, which works in our area, would also start paging BLS certified people in the neighborhood who have the app.

When I've called 911, the dispatchers grilled me going right down the list of signs and symptoms and did an excellent triage job.

I'm a volunteer EMT / FF at a pretty rural station, and the thing that slows us down the most is traffic if we're coming from behind the accident, and distance. As the sibling / gp said, the dispatchers know where we are via gps at almost all times and usually tell the RP (Reporting Party) when we're close so someone can go out and flag us down.

I don't mean to be argumentative, just provide what I know working as a volly FF/EMT for a year. As others have said, this is tragic.

FWIW, Seattle is famously one of the top cities in which to have a serious medical emergency. Very fast response and state-of-the-art care.