The nation's two largest wireless carriers both said they were waiving some charges retroactively to Friday, the day of the devastating 8.9-magnitude earthquake and tsunami. AT&T's free calls and texts - including up to 60 minutes in free calls from U.S. landlines - will continue all month. Verizon said its waivers would last till April 10, and would include all calls to Japan from U.S. landlines.