LONG ISLAND — For Long Island couple Anna and Salvatore Russo, when it came to keeping track of their savings account at Chase Bank, they relied on their signature card, paper withdrawal and deposit records.

That was in 2002.

But now, there’s a big problem.

“They lost it. They don’t know what happened to it – and they can’t explain it,” Salvatore Russo said. “And they feel they don’t have any obligation even though we have a book. I don’t see any right in that.”

The Russos are now suing J.P. Morgan Chase, one of the largest banks in the country.

After they opened the savings account 15 years ago, the couple acknowledges they left the money in the account for several years.

It was a long-term investment.

“So I told her the same thing. I said, ‘you must be kidding.’ And then I started laughing because I was friendly with them. I said there’s gotta be someone…