AT&T is still unsure of what caused a nationwide meltdown of its digital television service for several hours on Sunday. The outage affected an estimated 100,000 customers across 33 markets. AT&T is still unsure of what caused a nationwide meltdown of its digital television service for several hours on Sunday. The outage affected an estimated 100,000 customers across 33 markets. AT&T is still unsure of what caused a nationwide meltdown of its digital television service for several hours on Sunday. The outage affected an estimated 100,000 customers across 33 markets.
