Boston Marathon bombing one week on
22 April 2013 Last updated at 06:23 BST
A minute's silence will be held across the state of Massachussetts to remember the three people killed and 180 injured in the attacks a week ago.
It is still not known when a specially trained team of investigators will be able to question teenage suspect, Dzhokhar Tsarnaev.
He is under armed guard in hospital with a gunshot injury to the throat.
Jane Little reports.