For anyone who has friends running the Boston Marathon, it's reportedly been difficult to make calls to those in the city, and emergency officials don't want you to make calls anyway. (Texts are okay.) Luckily, the Marathon run tracker is, amazingly, still working. The explosion went off with 4:09 on the clock. It was a staggered start, meaning those at the finish line were running a 4:00 marathon. You can search for your runner, and compare it to the time of the explosion, here.
[Image via @GlobeDavidLRyan]