article_snippet: Timeline of the bombings, manhunt and aftermath .
article_snippet: When his brother's bomb went off a block away, heads swiveled in surprise in the direction of the noise.
article_snippet: Martin Richard, an 8-year-old standing in the line of kids, took the full brunt of the blast, which tore his brother apart.
article_snippet: The bombs went off at 2:49 and 2:50 p.m., about the same time as he exchanged phone calls with he .