It isn't just the gamblers losing money in Vegas these days. Nevada's 260 major casinos lost nearly $7 billion last year, ending in the red for only the second time ever.

To find one source of the problem, look no further than the bright lights of the Las Vegas Strip -- home to major properties for Wynn Resorts (WYNN), Las Vegas Sands (LVS) and MGM Mirage (MGM).

Casinos there took the bulk of the hit, reporting a $4.1 billion loss for the year, according to the Las Vegas Sun. That's a 686% drop from the previous year. The Strip casinos generally collect just over half of the state's gambling revenue.

"It was a horrendous year," the head of an industry group told the Sun.

This is just the second loss after a $33.5 million drop in 2003. That loss is peanuts compared to the high-stakes meltdown last year, however.

Shares of MGM Mirage dropped last week after the company reported a fourth-quarter loss of 21 cents a share, worse than the loss of 13 cents analysts were expecting.

Analysts told Reuters they were worried about hotel room pricing in the short-term. You can get a room at the MGM Grand for as little as $55 a night.

Las Vegas Sands is pinning all of its hopes to its operations in Macau, the only place in China where gambling is legal, Reuters reports. But even strong results in Macau couldn't save the company from a loss in the fourth quarter.

Wynn Resorts is expected to announce its fourth-quarter numbers on Thursday.