Pro wrestling is performed with the expectation of there being a live audience to interact with it. So moves, taunts, promos, and even entrance themes are engineered with consideration of getting crowds to react in specific ways. It’s why words like “pop” and “heat” are such big fans of wrestling lingo. If the crowd isn’t reacting, the performers have failed.

RELATED: 10 WCW Matches That Ended In Nonsense Ways

Sometimes, however, the crowd can get straight-up hostile -- either because the heel work was too effective, or because the fans really dislike something that was happening. Let’s take a look at ten instances of fans going buck wild and maybe even causing some wrestlers to fear for their safety.

10 “If Cena Wins We Riot” (ECW One Night Stand, 6/11/2006)

Ahead of ECW’s One Night Stand PPV, Rob Van Dam challenged John Cena to defend the WWE Championship on RVD’s turf, at ECW’s old stomping grounds of the Hammerstein Ballroom. Extreme Championship Wrestling had been dead for five years, but the fans there were still passionate, loudly and violently showing their hatred for corporate-approved WWE Superstar John Cena.

ECW fans were loud and angry, jeering his trademark World Wrestling Entertainment style of “sports entertainment” and literally throwing back his T-shirt when he tried to toss it into the crowd.

9 The Ric Flair Heel Turn (Mid-Atlantic Championship Wrestling/NWA Event, 9/29/1985)

Dusty Rhodes and Ric Flair in a brawl

A few months before their Starrcade ‘85 steel cage title match, Ric Flair turned heel on Dusty Rhodes at a show at the Omni in Atlanta. After a cage match between Flair and Nikita Koloff, Koloff’s goons attacked and Dusty ran in to make the save.

But Arn and Ole Anderson snuck up and attacked Dusty, while Flair locked them all in the cage together. Flair would injure Dusty’s leg, causing the crowd to go ballistic, rushing the cage and shaking the walls to keep the villains inside.

8 Cena vs. Orton for the 10,000th Time (WWE Royal Rumble, 1/26/2014)

The 2014 Royal Rumble PPV was mired in controversy. This is the one where Batista won the Rumble, CM Punk quit, and the crowd booed Rey Mysterio Jr. for coming in at #30 because they were expecting Daniel Bryan. But before the Rumble, John Cena challenged Randy Orton for the WWE World Heavyweight Championship, and the crowd couldn’t be more disapproving.

RELATED: 10 Wrestlers You Forgot Hold Victories Over Daniel Bryan

The 20-minute affair was the usual competent match Orton and Cena always had, but the Pittsburgh crowd, sick of this matchup and clamoring for WWE to push Daniel Bryan to the tops of cards, relentlessly heckled the whole thing.

7 The Pitbull #2 Incident (ECW Hardcore TV, 10/15/1996)

At 1996’s Heat Wave, Shane Douglas had legitimately broken Pitbull #1’s neck with a DDT gone wrong, but Pitbull #1 had healed up well enough to get involved in a match between TV Champion Douglas and Pitbull #2 months later.

Douglas grabbed Pitbull #1 by his halo neck brace and jerked him around, prompting fans to go nuclear, angry about the threat to Pitbull #1’s actual safety. Shane Douglas and his valet Francine had to escape the arena, fearing for their lives.

6 The One Time Sports-Based Heel Heat Worked (WWE Raw, 10/1/2018)

WWE loves to draw easy heat from live crowds by trashing the local sports team. It’s always a little baffling -- what do The IIconics care about the Toronto Raptors? -- but there’s one time it may have worked a little too well.

One time on RawKevin Owens took part in one Elias’ concert promos, focusing on Seattle’s loss of their precious SuperSonics basketball team. This turned out to be such a sore spot that the crowd vehemently booed Owens and Elias for several minutes straight.

5 The Cleveland Riot (NWF House Show, 1/31/1974)

Old school territory wrestling was awesome. Nobody had the Internet and people seemed to believe it was real, given the violent reactions crowds had to heel work. At a 1974 National Wrestling Federation show, Ox Baker turned heel on beloved local babyface “Big Cat” Ernie Ladd and repeatedly delivered his signature Heart Punch to the downed Ladd.

That is until fans started getting violent, rushing the ring and throwing chairs at the wrestlers, causing the performers to bolt.

4 Of Course They Did (ECW on Sci Fi, 8/1/2006)

This early episode of WWE’s version of ECW notably featured the debut of CM Punk but also had a main event where Batista challenged Big Show for the ECW World Heavyweight Championship. If that weren’t bad enough of an idea, they decided to do this in the Hammerstein Ballroom.

RELATED: 10 ECW Wrestlers We Can't Believe WWE Never Signed

As you might expect, ECW fans didn’t cotton to WWE nonsense, so the crowd trashed literally everything happening in front of them, chanting things like “you both suck,” “[expletive] this match,” “boring,” and “change the channel” -- all with liberal use of middle fingers.

3 Roman Reigns (WWE Raw, 4/3/2017)

The Raw after WrestleMania is always crazy, as the building is full of hardcore wrestling fans expressing hardcore wrestling fan opinions about WWE’s product. WrestleMania 33 had the controversial Roman Reigns seemingly retire The Undertaker, a fact that fans who did not like Roman to begin with really did not like.

Raw opened with Roman Reigns coming out to cut a promo only to get mercilessly booed by the live crowd -- especially whenever he raised his microphone to his mouth.

2 The Dudley Boyz Insult Dayton (ECW Heat Wave, 7/18/1999)

Bubba Ray ECW promo

In the middle of ECW’s Heat Wave PPV, Balls Mahoney and Spike Dudley were taking on The Dudley Boyz for the Tag Team Titles. Before the match, Buh Buh Ray and D-Von cut a nasty six-minute promo about Dayton, Ohio that involved a whole lot of language that hasn’t aged well.

The crowd was already booing, but Buh Buh Ray Dudley decided to escalate by throwing a drink in a fan’s face and getting an angry woman to spit on him.

1 The WWF Riot (WWF House Show, 12/15/1997)

Back in the ‘90s, the WWF would pre-tape Monday Night Raw, shooting a couple episodes at a time. In December of ‘97, they ran a house show on a Monday in Little Rock, Arkansas, so fans attending assumed it was going to be a Raw. A weak house show, lax security, and drunk, angry fans resulted in absolute chaos only exacerbated by Shawn Michaels announcing that the main event was cancelled after an object hit him in the head.

What ensued was a total riot, with stuff being set on fire, police shooting tear gas, a whole lot of arrests.

NEXT: 5 Ways Shawn Michaels Was Better In The '90s (& 5 Ways He Was Better In The '00s)