If you know someone who was running the marathon and haven’t heard from them, you can see if they logged times here:
http://raceday.baa.org/individual.html
Turns out my cousin's wife got injured in training and didn't run today. They were just there to cheer on some friends who were running. Last I heard they were OK, but, as you can guess, the flow of detailed information in and out of Boston is pretty patchy right now.