The PBP 2015 ending crash

I want to write up the 2nd 600K qualifying ride I did this weekend but it's going to be a long story.  Some people know I ended the ride with a crash and I wanted to get the details down while they're fresh.

I was riding south on the Centennial trail just past Arlington, and came up on this trail road crossing.  I'm riding from the top to the bottom of the picture with the red line.  This is at the intersecion 168th Street NE  and 67th Ave NE in Arlington:

As you can see, the two trail ends are not aligned so that a user can just ride across the road - they have to perform a sinuous S or U turn ON the road to get lined up with the other trail end.

This road has loose gravel on the edges that get kicked up onto the road and this is a pretty tight turn.  As I attempted the last part of the curve, something happened that caused the tires to lose grip and the bike slid out from under me and I went down hard on my right side.

So what was the cause?  Loose gravel? Soft tire? too much speed? Too tight a turn? Some or all of those, whatever - the bike went out from me and I went down hard on my right side. Head bounced off the pavement IN the helmet, but I wasn't wearing body armor and my ribs on the right side took a hard blow. After recovering from the shock of what happened, I pushed around and nothing felt broken, and I was breathing without any coughing up anything, so it almost seemed like I could finish the ride. I started down the trail but it was getting hard to take anything besides a very shallow breath. Any expansion of the chest was very painful, and it was getting worse. I looked up "bruised lung" on my phone and it said it could be fatal and usually got worse during the first 24 hours.  I decided trying to finish was foolish, and to get checked out, so I called 911.

It didn't take long for the Fire Department EMT to arrive and they asked a bunch of questions that make sense when you're examining a stranger, did a pulse Ox test (95) and Blood Pressure (normal) and asked if I wanted to be transported to the ER. I said yes.  I was taken to the ER where they asked the same questions (any medications? Blood thinners).  Doctor listened to my lungs and ordered X rays.   In the end, the doctor said I probably bruised the ribs and it should resolve in a week or two.

On the first day, it hurt to breathe deeply, cough, or bend down like to tie shoes.  Sitting still and breathing normally is not painful at all.  On day 2, it still hurt but started to get a little better through the day.  I took a sick day and just sat around all day, and that helped.

I don't have any room in my schedule for another 600, so this is the end of PBP 2015 for me. The ride reports both days are posted.  Thanks to everyone for your support - I was killing it -- until I wasn't.