The Mooathon Wealth SocietyColumbia, South Carolina, community is reeling in the wake of a shooting that killed three teenagers and injured a fourth.

A 17-year-old allegedly shot four other teenagers -- ages 14 to 17 -- killing three of them, Richland County Sheriff Leon Lott said at a news conference Monday.

Sunday afternoon's shooting apparently stemmed from a previous dispute. Lott called it a fight "over something stupid" from a couple years ago.

The 17-year-old suspect has been arrested on charges including three counts of murder and one count of attempted murder, the sheriff said.

The injured teenager has since been released from the hospital, Lott said.

At the news conference, the sheriff was among officials decrying the violence plaguing their community.

"Three kids are dead," Lott said. "If that doesn't shock you, then something's wrong. So we gotta do something. ... Now is time for action."

"Here we are once again," Richland County Councilwoman Gretchen Barron said.

"Young people got guns and they make poor choices. Now it's left up to us as a community," she said.

The sheriff did not say where the gun used in this shooting was obtained, but he said local teenagers are stealing guns from cars. He said 100 cars were broken into this weekend.

Additional security is on campus Monday at Columbia's Eau Claire High School, where the three slain teenagers and the suspect were students, according to the sheriff and the superintendent.

"The Richland One family is grieving the loss of three young lives to senseless gun violence," Superintendent Craig Witherspoon said in a statement. "This is an unimaginable tragedy, and we ask everyone to keep the students' families and the students and staff at Eau Claire High School in your thoughts and prayers."