Two people were killed and many more were injured after a mass shooting at a video game tournament in jacksonville, Florida.
The gunman is among the 'multiple fatalities' as the horror was captured live on the internet, with social media livestreaming as the shooting began.
Two people were dead and 11 injured, local media are reporting.
One suspect was "dead at the scene", police said.
The commentators could be heard going silent as the first gunshots were fired and people began screaming. The stream then cut out and a message appeared saying "controller disconnected".
Witnesses have said the shooter was a player who had just lost in the tournament.
One witness told CNN he saw the gunman shoot multiple people before killing himself.
Authorities say it has occurred at the Jacksonville Landing, a popular downtown area filled with restaurants and bars and a shopping centre on Sunday afternoon local time.
The Jax Sheriff's office warned the public via Twitter to "Stay far away from the area. The area is not safe at this time. STAY AWAY".
They later added: "We are finding many people hiding in locked areas at The Landing. We ask you to stay calm, stay where you are hiding. SWAT is doing a methodical search inside The Landing. We will get to you. Please don't come running out."
Fox News reported that several people on social media participating in the Madden NFL Championship Series reported hearing gunshots.
The event was being livestreamed and showed players reacting as gunshots were heard in the background.
The commentators could be heard going silent as the first gunshots were fired and people began screaming. The stream then cut out and a message appeared saying 'controller disconnected'.
One of the gamers, Drini Gjoka, said he was shot in the hand.
"The tourney just got shot up. I'm leaving and never coming back. I am literally so lucky. The bullet hit my thumb. Worst day of my life," he tweeted.
"I will never take anything for granted ever again. Life can be cut short in a second."
A reporter from Fox-affiliate CBS47/FOX30, Brittney Donovan, said that at least one person was seen being loaded onto a stretcher and into an ambulance.
Madden NFL 19 is a video game based on the NFL that's developed and published by EA Sports.
- Additional reporting Daily Mail