Right now, millions and millions of americans are lining up to take a chance on a giant dream. A powerball ticket that could be worth more than half a billion dollars. The biggest in its history. The... See More
Right now, millions and millions of americans are lining up to take a chance on a giant dream. A powerball ticket that could be worth more than half a billion dollars. The biggest in its history. The drawing is tonight. And some people have been willing to wait 2 1/2 hours in the long lines in arizona, while coast to coast, tickets are flying across the counters, 130,000 sold every minute. And that adds up to 7 million tickets sold every hour. So, we asked abc's steve osunsami to make his way into the vault from the lottery balls are kept under lock and key and tell us about all the americans hoping tonight is their night. Reporter: If this is lottery fever -- this is amazing. Incredible. That's the winner. The boats and the house and the cars. Reporter: Then millions are americans are trying to catch it. Buying lottery tickets like every before. More than 189 million powerball tickets sold in this final rush. Good luck. Thanks. Reporter: Late today, the lottery director told us she's pretty sure that when the numbers are dropped this evening, the jackpot will be even higher than that $550 million. And they'll announce it at the drawing. This is amazing. Incredi incredible, never happened here. Reporter: Families crowded mini marts and waited in endless lines, telling us they weren't just buying tickets, but hope and dreams. Best thing in the world. Nobody in my family would have to worry about anything ever again. 9:27. Reporter: We followed les sherman as he joined the multitudes outside this lottery retailer in arizona, just across the border from california and nevada, where powerball tickets aren't sold. He arrived at 9:00 this morning. Quarter to ten. Been in line for 30 minutes. Probably have another good 45, 50 minutes. One hour. Reporter: More than an hour later, les finally buys a ticket. Definitely going to win. Already spent the money. I better win. Reporter: I'm in the vault where they lock the machines. There's someone listening in on the phone, there's a briefcase, holding powerballs like these. And in just a short while, security will come in and move two of these lottery machines into the studio. At powerball's tallahassee studio, security is tight. There are seven surveillance cameras and two in the locked vault where the lottery machines are squirreled away. They are determined to avoid any where workers sub constituted weighed balls to rig the game. Because the integrity of the game is what is utmost important to us. The door to get in here is double locked, sealed and alarmed. Reporter: Employees who touch any of the lottery balls are required to wear gloves. These have been retired, not going to be used tonight and we were still told to wear gloves. These balls are not touched by human hands. That's to make sure no dirt adhere to the balls. Reporter: With so many tickets sold, lottery officials tell us there's a 75% chance, diane, that there will be a winner tonight. All right, thank you so much, steve. And something really surprised us today. Did you know that right now, americans have won $800 million but never claimed it? Includes those second and third place wins, by the way, so, be sure to check all the numbers on your ticket. You may have only 6 to 12 months to cash in.
This transcript has been automatically generated and may not be 100% accurate.