Josh Abbott Band at the Country Music Awards in 2015. Mike Stone/Reuters

Caleb Keeter, a guitarist with Josh Abbott Band who performed at the Las Vegas country music festival targeted by a gunman Sunday night, on Monday said he had changed his position on gun control following the attack that left 59 people dead and at least 527 others injured.

"I've been a proponent of the 2nd Amendment my entire life. Until the events of last night. I cannot express how wrong I was," he tweeted on Monday. "We actually have members of our crew with CHL licenses," or concealed handgun licenses, "and legal firearms on the bus. They were useless."

Keeter said his fellow band members didn't dare take out their weapons in self-defense as bullets rained down on the crowd from the 32nd floor of a hotel across the street "for fear police might think we were part of the massacre and shoot us."

"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 fire power," Keeter wrote. "Enough is enough."

President Barack Obama had used the same wording in 2015 in regard to gun violence, saying "enough is enough" after a shooting at a Planned Parenthood clinic in Colorado.

"If we truly care about this — if we're going to offer up our thoughts and prayers again, for God knows how many times, with a truly clean conscience — then we have to do something about the easy accessibility of weapons of war on our streets to people who have no business wielding them," Obama said then. "Period. Enough is enough."

Keeter added on Monday: "Writing my parents and the love of my life a goodbye last night and a living will because I felt like I wasn't going to live through the night was enough for me to realize that this is completely and totally out of hand. These rounds were just powerful enough that my crew guys just standing in close proximity of a victim shot by this f---ing coward received shrapnel wounds."

Keeter concluded: "We need gun control RIGHT. NOW. My biggest regret is that I stubbornly didn't realize it until my brothers on the road and myself were threatened by it. We are unbelievably fortunate to not be among the number of victims killed or seriously wounded by this maniac."

In response to comments from Twitter users who lamented the fact that Keeter and others changed their views only after being personally affected, Keeter said the criticism was justified and he would "like to do what I can now."

In another tweet on Monday afternoon, the musician struck a more optimistic note.

"That being said," he wrote, "I'll not live in fear of anyone. We will regroup, we'll come back, and we'll rock your f---ing faces off. Bet on it."