Proposing marriage has become an industry of its own with professional planners, flash mobs for hire and elaborate, homegrown surprises to make the moment memorable. And let’s not forget YouTube, and our steadfast resolve to share.

So what happens to the best laid plans when the ring goes missing, the liquid courage is out of control or romance is ruined by unforeseen disaster?

"More complicated equals more possible problems, and more pressure," said Anja Winikka, director of the wedding site TheKnot.com.

Val Hunt Beerbower, 29, learned that the hard way. She was a hot, bothered mess the night her husband, Mike, proposed during what he envisioned as a special evening taking in the sights of Washington, D.C. The Labor Day weekend weather was sweltering, she was exhausted from a full day on her feet and she stepped in a huge stagnant pool of foul-smelling water on the National Mall.

Her jeans wet and stinky, they pressed on toward the Jefferson Memorial, the proposal site he had scouted days before. Halfway around the Tidal Basin, her allergies kicked in, her glasses steamed up from the heat and humidity — and she was begging to return to their hotel.

"So in an unlit parking lot, within sight of the Jefferson Memorial, Mike popped the question," Beerbower, who works for a conservation group in Dayton, Ohio, recalled of their 2008 trek. While they were still basking in her "yes," a driver pulled up, opened his car door and threw up all over the place.

"Mike was crushed, but I couldn’t stop laughing," she said.

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Pam Cosce’s disaster came in frigid Paris last March, when her husband, Asa Sanchez, had it in his head that he would propose on top of the Eiffel Tower after dark, as close to midnight as he could get to honor a special visit there years prior.

He carried the ring around for 2 1/2 weeks but the tower was elusive. One night a boat ride returned them after it was closed. They were rained out another night. On and on it went.

"I didn’t even know what his obsession was because we don’t love Paris for its tourist attractions," said 43-year-old Cosce, who owns a landscaping business with her husband in San Francisco. "After 10 years together, it never occurred to me that he might be considering popping the question."

They eventually did make it to the top of the tower one night, but it was mobbed with people, including a rowdy rugby team and a chatty mother-daughter duo they couldn’t shake. Cosce and her beau escaped to the outside deck, straight "into a crazy, freezing windstorm." He was "positively verklempt" at the crowds and the weather, she said, so they made their way out and settled for a bench with a view of the Eiffel instead.

One thing that did go right: A little light he had installed in the ring box in preparation for his evening proposal actually worked.

YouTube and social media are full of big proposals gone wrong. There’s the girl who swallowed the ring her suitor buried in a strawberry milkshake, eventually accepting while holding her X-ray with a perfect view of her new rock. And there’s the brain surgeon who buried the ring on a Florida beach, only to forget where he put it when the time came.

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And there’s 30-year-old Hans Krauch, an aviation technician from Victoria, British Columbia. The AP hunted him down online, along with Beerbower, Cosce and others who agreed to interviews.

"I was totally hammered when I did it. I needed the liquid courage. Her reply was, ‘Yes, but when you sober up you better still feel the same,’ " he recounted of his mumbling, bumbling question he loosely calls a proposal. They now have a 2-year-old daughter.

"The plan was just do it and get it over with, kind of close your eyes and just run in, guns blazing," said Krauch, who doesn’t necessarily recommend his without-a-plan approach. "Taking the next step forward is always a challenge."

So how does his wife feel about it now?

"I think she’s a little embarrassed because a lot of her friends are, you know, beautiful dinners, flowers, the whole thing, the traditional thing, and then this. I deliver this," he said sheepishly.

Preserving a proposal on camera is an important moment, Winikka said: "These days we’re not shy to share. We’re all exposed to one another’s lives." And what better way than creating a public event or sweeping a beloved off to a romantic destination — two strong trends, she said.

Social scientists haven’t spent much time studying marriage proposals, but Winikka said tradition still reigns amid the madness to go big and go public.

She said 71 percent of about 10,000 newly marrieds who used her site noted their betrothed asked a parent for permission before popping the question, and 77 percent of grooms went down on bended knee. More couples live together before they get hitched, she said, adding to the desire for meaningful proposals.

"Couples are looking to create something really special and create a moment," Winikka said.

Things didn’t go quite as planned for Tarek Pertew, 30, in Brooklyn. He was married about four years ago with no fanfare and no engagement ring, so he decided he would officially ask his wife to "stay married" on Dec. 16, the fifth anniversary of the day they met.

A lover of graffiti and street culture, Pertew felt lucky when he discovered a slab of wet concrete near their apartment. He carved the proposal there two weeks before the date, only to have it smoothed over, except for a bit of his footprint.

He soldiered on, despite a prescient dream his wife had that he would propose to her in a nearby park. Then came a New York moment.

"The evening before, I do a dry run and notice that a massive pile of dog poop was sitting right on top of the sidewalk square," said Pertew, who owns a media company. It was too late to change course, so he cleaned it up as best he could in a drizzle, leaving an unsightly smear.

She said yes, and Pertew hopes: "At least my footprint can symbolize my intent."