DESPITE suffering a secret collapse during a recent trip to Los Ange­les, Liza Minnelli is determined to hit the road for a grueling tour – and worried pals fear it will kill her!

“I wouldn’t be surprised if she dropped dead onstage,” said a friend.

The 67-year-old performer certainly looked to be in no condition to tour while she was in L.A. to attend the Jan. 19 Screen Actors Guild Awards.

Recent pix showed the “Cabaret” star appeared wobbly on her feet and two men helped her walk the red carpet. Later, the barely recognizable showbiz legend had to use a wheelchair to get through LAX airport on her way back to New York.

So what happened?

The ENQUIRER has discovered that between the SAG Awards and her trip to the airport, she suffered a mysterious collapse that has people close to her very concerned.

“Liza can no longer walk unaided, which is why she needed help at the red carpet event,” explained the friend. “And after the collapse that put her in a wheelchair, there are fears that she could die soon.”

Along with her physical ailments, sources say Liza has become increas­ingly blue in recent months.

“She’s so sad and lonely,” said the friend. “She misses her departed friends, like Michael Jackson and Elizabeth Taylor. That’s one reason she flew out to the SAG Awards – she wanted to experience the glamor of Hollywood ‘one last time.’ But it was just too much. Her health is a lot worse than anyone knows.”

Liza’s had a long history of battling booze and drug addictions and has suffered several health woes requiring hip and knee replacement as well as other surgeries. In October, she broke her wrist in three places while rehearsing at home.

“What she’s been through is taking its final toll,” said the friend.

When contacted by The ENQUIRER, Liza’s longtime rep Scott Gorenstein said our sources’ claims are “completely ri­diculous” and that Liza did not suffer a collapse but sometimes uses wheelchairs at airports. He added that she’s still plan­ning to hit the road for her “Simply Liza” tour that’s slated to kick off on Feb. 16.

But worried pals fear Liza will be in no condition to tour.

“It’s tragic,” said the friend. “We may soon lose one of America’s greatest stars.”