I'm thinking it must be something fatal then. Probably a huge accident.
This reminds me of last year I was coming home from work but my street was blocked by at least 10 cruisers, an ambulance, lot of people standing/walking around and other various vehicles. Was hard to tell what happened but I feared it may be a dead kid given there's a school near by.
Sure enough, it was a little girl that got ramed through the fence by a guy driving a pickup. he was not drunk or anything, never heard the real story but it turns out he had some kind of caugh attack and he lost control and his foot floored the pedal.