Maui Mayor Alan Arakawa says iPhones were useless to emergency officials trying to coordinate a response to a tsunami from Japan.

New iPhones carried by emergency responders were not working during tsunami preparation on March 10, Arakawa told KITV-TV. Officials had to resort to other communications including a walkie-talkie system.

Big Island officials and AT&T customers on Oahu also reported similar service problems the same day.

An AT&T spokeswoman said Monday its cellular system was simply overburdened. The number of calls the night leading up to the tsunami was five to six times more than normal.

Arakawa says he was never told of a potential overload problem with Maui County’s choice of AT&T as a service provider.

AT&T says the acquisition of T-Mobile should help increase capacity.