LINCOLN, NEB. ? The sole winning ticket for the biggest jackpot in Powerball history was purchased at a Nebraska convenience store, lottery officials said Sunday, as they patiently waited for someone to step forward and claim the $365 million prize.

As a Powerball frenzy was building across the country last week – retailers sold 29 tickets per second in West Virginia alone one day – a customer who was standing in line at 3:09 p.m. here Friday unwittingly walked away with the ticket that ultimately carried the six lucky numbers.

“We have it narrowed down to five people,” said Mick Mandl, the owner of the U-Stop convenience store on the edge of downtown Lincoln, who reviewed security footage with lottery officials on Sunday. “But we didn’t recognize who it was.”

When he learned the ticket had seen sold at his store, tucked between fast-food restaurants and used car dealers, Mandl said he was dumbfounded. After lottery officials pinpointed the precise time the ticket was purchased, he began poring over videotape from three security cameras that are trained on his cash registers, hoping to find that the winner was one of his regulars.

As Sunday passed without a peep from the actual winner, the silence gave way to a daylong game of 20 questions inside the store. Was it someone who had come to the store specifically to buy lottery tickets as the jackpot grew? Was it someone just passing through the state capital? Or, perhaps, was it someone from the People’s City Mission, the local homeless shelter, which sits only a block away?

Mick Mandl, left, co-owner of the U-Stop franchise at First and West O streets in Lincoln, Neb., visits with Tom T.J. Johnson, events and media coordinator of the Nebraska Lottery Sunday, Feb. 19, 2006, about the record 65 million winning Powerball ticket that was sold at his store in Lincoln, Neb.

“Wouldn’t it be great if it was somebody down on their luck who got the $365 million?” Mandl said. The chances of matching all six numbers – 15, 17, 43, 44, 48 and Powerball 29 – were 1 in 146.1 million. The sole winning ticket was a “Quick Pick” in which the numbers were selected at random, lottery officials said.

If the winner elects to take the money in one lump sum, the cash option is $177.8 million, or $124.46 million after taxes. Or the first payment on the installment plan is $6.5 million after taxes.

Brian Rockey, the communications and marketing director for Nebraska Lottery, said in an interview that it was not unusual for a winner not to immediately come forward. At the earliest, he said, the winner would not be revealed until after the Presidents’ Day holiday today.

“Even if someone were to call and say, ‘I’ve got the ticket,”‘ Rockey said, “we’d say that’s great, but we’ll see you on Tuesday.”