Massive AT&T Outage Affects Customers In Brentwood

LOS ANGELES, CA — An outage caused by a software glitch affected AT&T business voice customers Monday in cities across the U.S., including Los Angeles.

In addition to Los Angeles, service problems affected AT&T business voice clients in major cities such as Dallas, Houston, Miami, St. Louis, Chicago, New York and hundreds of other areas, according to downdector.com.

`We apologize to our customers who were affected," AT&T said in a statement that acknowledged "an issue affecting some of our business voice customers."

It was not immediately clear how widely the outage -- which the company attributed to a software issue -- affected AT&T's business voice customers in Southern California.

But Cedars-Sinai Medical Center emailed clients and others to say that its land lines were "not receiving calls from the outside" and also announced about 9:40 a.m. via Twitter that its phones were down "due to a nationwide AT&T outage."

Another tweet issued at 11:09 said the Los Angeles hospital was not receiving incoming calls. At 1:11 p.m., Cedars-Sinai announced that service was "returning and should be fully restored later this afternoon."

City News Service; Image: AT&T outage map