U.S. FCC probes why AT&T customers could not call 911

By David ShepardsonWASHINGTON (Reuters) - The U.S. Federal Communications Commission said on Thursday it will investigate why AT&T wireless subscribers in several states could not make emergency 911 calls late Wednesday.The FCC has previously fined carriers that had 911 outages that it deemed preventable and required steps to prevent further outages.“Every call to 911 must go through,” FCC Chairman Ajit Pai said in a statement.