Former US President Bill Clinton has tweeted:
One year later, inspired by so many stories of survival and hope. My thoughts are with Boston today. #BostonStrong
More top news
Jeremy Corbyn is facing increased pressure to resign as Labour leader.
A group of schoolchildren who went missing in the Brecon Beacons are being brought back to safety by rescue teams.
Another unsettled day with cloud, rain and blustery winds.