The WSOP poker room and other casinos descended into chaos when rumors of an active shooter on the Las Vegas Strip sent players into a panic.
Some ran out into the halls in what was described as a "stampede", while others threw themselves to the floor and hid under poker tables.
But some sat calmly in their seats, cool as cucumbers, chatting away as if nothing had happened.
Daniel Negreanu posted a picture of his bloodied hand, injured in the melee. Another showed off his bruised leg.
In the event, there was no shooter.
As it happened, a glass door had allegedly shattered at the MGM, and rumors spread like wildfire that a shooter was on the loose.
It took the Las Vegas Police Department to post an outright denial to calm things down.
Videos began to emerge of members of the public running at various casino locations. There were reports of some people panicking as far away as New York, New York, The Cosmopolitan, Excalibur, and the Bellagio.
WSOP officials, after initially asking everyone to leave Paris, then reassured players, dealers and floor staff that the area was safe and that they could return to the tournament areas.
However, it was expected that getting back to normal might take a little time.
Negreanu posted a graphic photo of his injured hand, which we prefer not to publish in case readers are not fans of blood.
Joey Ingram caught the moment that panic swept the area, responding to Negreanu's Tweet about his injured hand.
Others also Tweeted scenes as panic mounted.
The drama came after Norwegian Espen Jorstad had won the WSOP Main Event for $10,000,000.
But other tournaments were still being played out in Paris, including The Closer and a daily deepstack event. WSOP officials announced chips were being bagged, and "some tables in the Closer need to be reconstructed."
While widespread panic might appear to be an overreaction, nobody can forget the 2017 shooting in the city, where 60 festival goers were killed.
