Artifacts, condolences mark Boston Marathon exhibit

A banner featuring messages of support and condolence from members of the armed services at Bagram air base, in Afghanistan, was part of the original memorial to bombing victims near the finish of the 2013 Boston Marathon.   (Steven Senne / Associated Press)

The banner from service members at Bagram air base, in Afghanistan, rests on a table at the city archives in Boston. Thousands of items from the original memorial are going on display at Boston’s Central Library.   (Steven Senne / Associated Press)

A placard featuring hand-written messages for victims of the Boston Marathon bombing rests on a shelf at the city archives in Boston. Thousands of items from the original memorial are going on display in the exhibit “Dear Boston: Messages from the Marathon Memorial,” which will open April 7 at the Central Library in Copley Square.  (Steven Senne / Associated Press)

Kevin Brown of Boston, right, places a teddy bear at a makeshift memorial to the victims of the April 15 bombings near the Boston Marathon finish line, in a May 7, 2013, image.   (Steven Senne / Associated Press)

Memorials for Martin Richard, Lingzi Lu and Krystle Campbell, killed in the Boston Marathon bombings, stand among other artifacts at a memorial in Boston’s Copley Square. The crosses and other items from the memorial are part of the exhibit opening April 7 in the Central Library in Copley Square.   (Matt Rourke / Associated Press )