After four people were killed and 32 others, mostly teenagers, were injured in a shooting at a 16th birthday party in a small city in Alabama on Saturday night, residents returned to work and school on Monday with no official information about who opened fire or why.

On Monday evening, the Alabama Law Enforcement Agency said police were still processing evidence and had recovered shell cases from the shooting at the Mahogany Masterpiece dance studio in Dadeville, which has a population of about 3,000 people and is about 60 miles northeast of Montgomery. No evidence of high-powered rifle ammunition was found, the agency said in a statement.

The Tallapoosa County Coroner, Mike Knox, on Monday identified the four victims who died as Shaunkivia Nicole Smith, known as Keke, 17; Philstavious Dowdell, 19; Marsiah Emmanuel Collins, 19; and Corbin Dahmontrey Holston, 23.

Community leaders, including the police, school officials and clergy members, described the town as close-knit. The shooting at about 10:34 p.m. on Saturday night shattered that placid atmosphere. Officials have not said if they have identified a suspect or suspects, made any arrests or found a motive.

Seven miles outside the city, on Highway 280, a digital billboard above an auto dealer had become a roadside memorial. One image said “Pray for Dadeville,” and the screen advanced through pictures of the victims, including Alexis Dowdell kissing her brother Phil on the cheek and Keke Nicole Smith smiling on the sidelines of a game.

“Dadeville is a very small community. It’s just really difficult,” Heidi Smith, a spokeswoman for Lake Martin Community Hospital in Dadeville, said at a news conference on Monday morning.

The hospital treated 15 teenagers with gunshot wounds, she said. Six had been discharged and nine were transferred to other hospitals. Of the nine, five were in critical condition and four were in stable condition.

Ms. Smith said that the hospital staff had undergone training for shootings and other crises, but there was no way to actually prepare.

“It’s very traumatic in a health care setting, an emergency room setting, when you have one gunshot wound come through,” Ms. Smith said. “But when you have 15, and they are all teenagers — our staff has been through a lot.”

Ms. Smith said that the hospital would provide free counseling to its staff as well as to children at the high school and the families of the victims. She said a hospital worker on the night shift had called to ask to be first in line for help.

James Ryan, a native of Calera, Ala., who had moved to Dadeville in 2016 and chose to stay there because he found the city safe and quiet, lamented the violence taking young lives.

“I just hate that this happened here,” Mr. Ryan said. “There’s got to be something done about the guns.”

The United States is an extreme outlier for gun violence, especially in its high number of young victims, compared with similarly large and wealthy nations. In 2020, gun violence surpassed car accidents and disease to become the leading killer of children.

Dadeville had experienced a shooting with multiple victims in August 2016, when five people were shot at a party in the American Legion Hall, less than half a mile from the dance studio where the shooting took place on Saturday.

The dance studio is in an old bank building on North Broadnax, a main thoroughfare that runs though the historic downtown business district. On Monday morning, the American flag and the state flag flew at half-staff at city buildings and the front doors of the Dadeville Public Library were draped in ribbon-wreaths of black and gold, the local high school’s colors.

Two of the teenagers who were killed in the shooting were seniors at Dadeville High School.

Shaunkivia Nicole Smith was a volleyball player and team manager for the high school’s track team. Michael Taylor, who coached the track team that Ms. Smith managed at Dadeville High School, described her as “full of life.”

Mr. Taylor said on Sunday that the shooting was at a birthday party for the younger sister of one of the victims, Philstavious Dowdell, who was a Dadeville High School football player. Mr. Dowdell had committed to Jacksonville State University. The head coach of the university’s football team, Rich Rodriguez, said in a statement that Mr. Dowdell was a “great young man with a bright future.”

Mr. Dowdell’s sister was a cheerleader who cheered for every sport at the high school and many of the athletes had come out to her party to celebrate, Mr. Taylor said.

Corbin Dahmontrey Holston had played basketball and football at Dadeville High School. Marsiah Emmanuel Collins, 19, had played football at Opelika High School, which is about 26 miles southeast of Dadeville.

Mr. Collins’s father, Martin Collins, told AL.com that his son had graduated in 2022 and had planned to attend Louisiana State University in the fall.

“He was a great big brother to his sisters,” Mr. Collins said. “He was a funny, charismatic kid who loved to light up a room.”

Claire Fahy contributed reporting. Susan C. Beachy contributed research.