"Yeah, take a photo in front of the stage where people died. Really classy," wrote a second.
"Didn't people die here? Maybe not the cutest insta post?" said another.
"People literally died trying to get over that mountain."
Since the backlash, the post appears to have been taken down.
Hundreds of comments agreed the post was "tone-deaf". Meanwhile, 13 people remain in hospital with injuries as a result of the crowd surge. More than 300 were treated for their injuries on concert grounds.
Investigators are looking into the design of safety barriers and the methods of crowd control in determining the cause of the deaths.
Officials said the investigation will include reviewing video footage from Live Nation as well as clips taken by those at the show. They will also be reviewing the event's security plans to see if they were properly followed.
Rapper Travis Scott shared in a tweet that he was "absolutely devastated" by what happened and would be working "together with the Houston community to heal and support the families in need".
In a similar statement, Live Nation shared on Twitter: "Our hearts are with the Astroworld festival family tonight – especially those we lost and their loved ones.
"We are focused on supporting local officials however we can. With that in mind, the festival will no longer be held on Saturday.
"As authorities mentioned in their press conference earlier, they are looking into the series of cardiac arrests that took place. If you have any relevant information on this, please reach out to the Houston Police."
