A Globe photographer's eyewitness account of the Boston Marathon bombing

[CONTENT WARNING: This video contains graphic images that may be disturbing.] Coming Tuesday, Boston Globe Today, our new show in partnership with NESN, will debut at 5 p.m. on NESN. It will also stream on bostonglobe.com and on NESN 360. Each day, we'll take you behind the scenes of stories that have the region talking, and sit down with reporters to dive deeper. Here's a preview of what you can expect. Ten years after the Boston Marathon bombing, we spoke with Globe photographer John Tlumacki, who was at the finish line when the bombs went off a decade ago and captured the devastation with his camera.