NYPD activity on Upper East Side

I decided to walk home from work yesterday. As I walked up 3rd Ave, I could see some police activity ahead at 86th street but didn't think anything of it. I cut down 84th street and as I got to the middle of the block, a box truck got stuck behind a doubleparked car and started to honk. About 15 seconds later, I hear someone over my headphones yelling "hey Joe, hey Joe" and getting louder quickly. I turned around there's a bike cop barreling down the sidewalk towards me at like 35mph- he's only about 10 feet away and saying "watch out". There was not enough time to react and he nearly knocked me over as he passed, his handlebars were easily within 6 inches of me.

Then when I got towards the corner, I hear a siren coming down the street from behind me and an undercover car comes flying down the street, skidding around the corner Blues Brothers style, heading south on 2nd Ave. I look up towards 86th and see more police lights up there. Obviously something is going on. Heading up to 86th and 2nd I see a police van blocking traffic on 2nd:
There didn't appear to be an accident or anything and the cop was letting cars go around him slowly. I was confused. When I got to 1st avenue, I saw the same thing blocking traffic heading uptown:

Now I was completely baffled. Today it's all explained, sort of. The Daily News reports that a cop died near 3rd Ave after giving chase to some burglary suspects. That makes sense with the bike cop and undercover car, but why were they blocking off traffic on 2nd & 1st? Maybe to clear a path down 86th? And how come bike cops don't have horns or bells?

category: nyc_