Police respond to gunfire in downtown Jacksonville Beach, Florida, on Sunday, March 17, 2024.
CNN  — 

One person was killed and three were injured after gunfire erupted Sunday, prompting police to shut downtown Jacksonville Beach, Florida, as it was packed with spring break visitors celebrating St. Patrick’s Day.

The gunfire – which erupted in three separate locations – began when police broke up a group of 250 to 400 teenagers who had gathered under a pier and were staging fights, Jacksonville Beach Police Chief Gene Paul Smith told reporters Monday.

It was just one episode in a spate of deadly gun violence that erupted across the country over the weekend, including shootings that left two people dead and five injured in Washington, DC, and three people dead – including the accused gunman’s 13-year-old sister – in Pennsylvania.

The Jacksonville Beach shootings came after Republican Gov. Ron DeSantis deployed state troopers to cities around Florida this month to help manage spring break crowds.

That decision followed a year after Miami Beach was forced to issue a state of emergency and midnight curfew following fatal shootings during last spring break season.

And in Volusia County last week, sheriff’s deputies confronted and arrested a 16-year-old after he pulled a gun out in a crowd of spring breakers, according to a police social media post Thursday.

Here’s how the gun violence in Jacksonville Beach unfolded:

Around 7:50 p.m., after police dispersed the crowd under the pier, two people near a Best Western hotel shot at each other. Both were wounded and so was a bystander. Two of the three wounded remain in serious condition, Smith said Monday. One of the suspects, who Smith said is known to police as a gang member, self-reported to the hospital.

At around 8:13 p.m., officers saw a man display a pistol and fire a shot as he ran by a bar. A foot chase with officers ensued, Smith said, but the suspect got away. No one was injured, Smith said.

Around 8:30 p.m., police responded to another shooting behind another downtown bar. A 21-year-old man was killed, Smith said, describing the suspect as a 6-foot-tall Black male with a short beard.

Because they were dealing with multiple unknown shooters and victims, police decided to issue an active threat alert, lock down all bars and evacuate the downtown area, Smith said.

Authorities issued a shelter in place order for the area that was lifted shortly before 11 p.m. The police department also brought in a SWAT team to help look for remaining suspects and escort patrons from businesses, Smith said.

No officers fired weapons during the incidents, showing “amazing restraint” and concern for the “thousands of people running around them” in the downtown area, Smith said.

Smith urged anyone with information about the shootings to come forward to assist police in the ongoing investigation.

This is a developing story and will be updated.

CNN’s Amy Simonson contributed to this report.