Hundreds of Dallas passengers were looking to catch another flight or hotel room in North Texas after a massive outage at the nation's busiest airport in Atlanta on Sunday.

Dallas-Fort Worth International Airport listed a dozen flight cancellations Sunday afternoon and evening for both American and Delta Airlines.

Delta operates a hub out of Atlanta Hartsfield-Jackson International Airport.

Southwest Airlines says seven direct flights (three to Atlanta and four to Dallas) were canceled out of Dallas Love Field on Sunday. An additional five Southwest flights bound for Atlanta from Dallas did not make it past planned stops in Austin and Houston.

The net effect at DFW was long lines at the ticket counter at Terminal E where Delta saw the majority of cancellations.

Bianca Collazo landed at DFW on a flight from San Francisco. The Atlanta native said she didn't learn of the power outage until her brother texted her upon landing.

"He said the power has been out since 1 p.m. and you're not coming home tonight," Colazzo said.

Ernest Henderson was looking to see if his 9 a.m. flight on Monday to Atlanta was still in place.

"They say it is for now," Henderson said. "I will have to come back tomorrow to find out. The total airport being shutdown? That's just unthinkable."

Late Sunday the Atlanta Airport said utility provider Georgia Power believed "the issue may have involved a fire which caused extensive damage in an underground electrical facility," according to a statement.

WFAA asked DFW Airport officials Sunday night about the availability of backup power and redundant systems.

"I"m confirming DFW has built-in redundant power sources," a spokesperson said Sunday night.

Southwest Airlines told passengers to keep checking the airline's app and website to get updates on flights early Monday morning.

Power was back on in Atlanta early Monday morning. TSA checkpoints reopened at about 3:30 a.m.