One of the performers at Sunday night’s country music festival in Las Vegas is changing his tune on gun control after witnessing first-hand the massacre that killed 59 people.

Caleb Keeter, a guitarist for the Josh Abbot Band, sent an emotional tweet Monday, describing the fear he and his bandmates faced, as well as his changing opinion on gun control.

“I’ve been a proponent of the 2nd amendment my entire life, until the events of last night,” Keeter tweeted. “I cannot express how wrong I was.”

The 2nd amendment in the United States is known as “the right to bear arms,” meaning Americans have the right to carry firearms.

Keeter and the Josh Abbot Band had performed just hours before a gunman rained bullets down on the crowd of roughly 22,000 at the Route 91 Harvest Festival from a nearby Las Vegas hotel.

At least 59 people are dead and another 527 are injured in the deadliest shooting in modern U.S. history.

“A small group (or one man) laid waste to a city with dedicated, fearless police officers desperately trying to help, because of access to an insane amount of firepower,” Keeter wrote.

“Enough is enough.”

Some crew members of the Josh Abbot Band have legal firearms on their tour bus, but couldn’t use them due to fear that police might think they were part of the shooting, Keeter wrote.

“They were useless.”

Keeter stated that while in hiding, he wrote to his parents and the “love of my life” to say goodbye because he thought he wouldn’t survive the night.

One of the band’s crew members suffered shrapnel wounds after the gunman shot someone nearby.

“We need gun control RIGHT NOW,” Keeter wrote. “My biggest regret is that I stubbornly didn’t realize it until my brothers on the road and myself were threatened by it.”

Shortly afterwards, Keeter sent out a second tweet, making sure everyone knew this shooting would not impact the band’s performances.

“(I will) not live in fear of anyone,” he wrote. “We will regroup, we'll come back, and we'll rock your f------ faces off. Bet on it.”