Not only are we surrounded by three major hospitals, but the Seattle Fire Department has established a fire station at Harborview for 5 Medic units (Aid units come up under I-5 from the International District station). SFD also dispatches Medic units from Harborview to the northern parts of downtown: to avoid congestion, they go straight down 9th Ave to Seneca, then drop down across I-5 to their destination. So almost half the outbound sirens we hear are nothing local. Most sirens are private ambulances such as AMR; this is a puzzle because most are not urgent (Medic units transport the patient without waiting around).
As of December 18, the Seattle Fire Department log of non-police 911 calls has shifted to http://SFDlive.com, a considerable improvement in web design, though you can still find the older-style log sheet at http://www2.seattle.gov/fire/realtime911/getRecsForDatePub.asp?action=Today&incDate=&rad1=des.
Interesting, Bill! As far as I could tell, none of the sirens stopped at 725 9th Ave.!