Boylston was still cordoned off and deserted except for a half dozen lab technicians hard at work a quarter mile away, small white-coated shapes across an eerie urban landscape.
Historians have watched the rise of these stunning, organic, "makeshift" memorials over the past few decades. (Michael J. Lewis of Williams College has a particularly good essay on the topic here.) They make powerful if fleeting statements, not unlike the memorials that arise on Facebook or other social media sites. This particular one at Boylston was very sad and very moving. Lots of people visited--fittingly, many runners who apparently stopped by as part of their Saturday morning workouts--and everyone to a person was quiet and most respectful.
What's particularly healing for me about this sort of makeshift memorial is that, while it will disappear soon enough, I will never cross Boylston Street again without seeing it in my mind's eye. I don't know if it can ever crowd out the other awful images, but it's not a bad start.
Ironically, the most lasting monuments of all are sometimes those that just fade away.