Now, that is scary to a grandma who just took daughter and granddaughter to London for a week. I did have a backup ATM card but relied on the B of A one heavily. Thankfully I didn't have the problem, but if/when we go back I'll keep my fingers crossed (and another ATM card or two in my purse).
BoA is in cahoots with Barclay in the UK. Probably not as big an issue if you use an affiliate. Still a good idea to let them know you're out of the country.
I also check my e-mail accounts as I have gotten fraud alerts that way. By checking e-mail I can respond fast if there is an issue.