A gunman opened fire on Sunday night on the Las Vegas strip during a concert where country music artist Jason Aldean was playing.
At least two people have been reported dead from the mass shooting incident, which took place around the Mandalay Bay casino area.
As with all such incidents of mass violence, images and video were shared quickly on social media and were picked up by media outlets.
Here's what you should know before sharing information about such an event:
1. Always check the information rings true with official sources:
In this case the below comes from the Las Vegas Met Police Twitter, but you should check what emergency services are saying about an incident, especially if it discounts the account you're about to share.
We're investigating reports of an active shooter near/around Mandalay Bay Casino. Asking everyone to please avoid the area. #LVMPDnews
2. Send your information to the right people, not to Twitter.
Emergency services are often appealing for information after this sort of attack. If you think you have information that is important, send it to authorities, not to Twitter.
As the police account pointed out, you shouldn't take photos or livestream the position of response units either - you could be putting officers in danger by broadcasting their location.
3. Don't share graphic images of victims
You don't have a right to inform the families of victims of any possible harm that has come to them. If someone has been injured or lost their life, informing loved ones of that is a delicate and often upsetting responsibility that police and specially trained staff handle very carefully.
Also, the people who follow you do not have a need to see graphic violence and may be distressed.
4. Report deliberate misinformation
If you see someone deliberately sharing misinformation for any means on Twitter, you can report them to the social media network for doing so.
Just click the drop arrow at the top right of a tweet, and click 'report tweet'.