Two children killed in shooting that left gunman dead at Gilroy Garlic Festival in San Francisco Bay Area

What we know:

• 3 killed, including a 6-year-old boy, a 13-year-old girl and a man in his 20s, and 12 others wounded in a shooting at the popular Gilroy Garlic Festival some 80 miles southeast of San Francisco
• Gilroy police quickly shot and killed a gunman
• The deceased gunman has been identified as Santino William Legan, 19
• Authorities are investigating whether a "potential second suspect" was involved in the plot
• 5 remain hospitalized, with three in serious-to-fair condition

A young boy, a teenage girl and a young man were killed in a mass shooting at a Northern California garlic festival that left a dozen other people wounded, police said Monday. The 19-year-old gunman, who also died in the Sunday evening shooting at the Gilroy Garlic Festival, bought his "AK-47-type" weapon legally in Nevada, Gilroy's police chief said.

The deceased victims were identified by officials as 6-year-old Stephen Luciano Romero of San Jose, 13-year-old Keyla Salazar and Trevor Irby, who the police said was in his 20s. The medical examiner's office identified Romero overnight, and Irby was identified Monday by the president of his alma mater, Keuka College in upstate New York.

During a Monday morning press conference, Gilroy Police Chief Scot Smithee confirmed the gunman has been identified as Santino William Legan, 19. The police chief said investigators haven't found a motive for the shooting.

"Anytime a life is lost it's a tragedy, and when it's young people it's even worse, and it's very difficult," Smithee told reporters. "... It seems that this was a random act, but, again, we've got a long way to go before we can come to a determination what his motivation was."

Smithee told reporters in a late-night briefing that Gilroy officers engaged the gunman within a minute of shots ringing out and killed him.

13-year-old victim may have saved relative's life

A family member of a 13-year-old girl who was killed by a gunman at the Gilroy Garlic Festival in California told The Associated Press that the teenager may have inadvertently saved another relative's life.

Keyla Salazar's aunt, Katiuska Vargas, said the teen was eating ice cream with family members when they heard gunshots and began to flee. Vargas says her niece stayed back to keep pace with a relative who uses a cane and was shot with a bullet that otherwise might have hit that woman.

Vargas says Keyla's stepfather was wounded as he went back for her.

Keyla's two sisters, ages 4 and 12, also were at the festival, but they escaped unharmed.

GoFundMe launches crowdfunding page for victims

The crowdfunding website GoFundMe created a page with verified fundraising campaigns for victims and those impacted by the Sunday shooting. This includes pages for the families of six-year-old Stephen Luciano Romero, 13-year-old Keyla Salazar and 25-year-old Trevor Irby as well as a woman injured in the shooting.

Vigils held for victims

Multiple vigils were held for victims and those impacted by the shooting. One bilingual vigil took place Monday night at St. Mary's Parish in Gilroy.

Another vigil, organized by a community member, was being held in a plaza between the town's library and city hall and included music performed by the Christopher High School choir. One attendee suggested merging the vigils as a show of solidarity.

5 remain hospitalized

Five people remained hospitalized at the Santa Clara Valley Medical Center, Trauma Medical Director Dr. Adella Garland said during a press conference Monday evening. Of the five patients, three are in serious to fair condition, while two declined to offer updates on their medical condition.

Dr. Garland said that the hospital learned much from the military as well as other shootings on how to respond. She and Dr. Peter Coelho, the medical director of the St. Louise Regional Hospital in Gilroy, credited their dedicated staff for effectively treating patients.

FBI launches website for video and photo tips

Deputy Special Agent Craig Fair of the FBI's San Francisco branch announced during a Monday press conference that the agency had launched a website for the public to send photos or videos related to the shooting. Fair said he expects it to take a few days before authorities have swept the crime scene, which he described as "extensive and complex."

Fair said that authorities were looking into social media tips as well. Gilroy Police Chief Scot Smithee mentioned that officials looked into the Facebook profile of "Chase M. Killings," which may have belonged to someone involved in the shooting. After taking the person into custody, authorities determined that he was "not associated with this event."

Gun retailer condemns selling weapon to suspect

The retailer believed to have sold the weapon used in the Sunday shooting issued a statement on Facebook condemning the tragedy, saying "it goes against everything I believe in."

"I pray to God for all the families. I did not know this individual. He ordered the rifle off my internet page. When I did see him, he was acting happy and showed no reasons for concern," Big Mike's Gun & Ammo wrote. "I would never ever sell any firearm to anyone who acted wrong or looks associated with any bad group like white power. Everyone is my brother and sister and I am mourning for the families."

"Potential second suspect"

Smithee had said witnesses told authorities at least one other person may have been involved in the shooting, but there was no confirmation of that or the role he or she might have played. At Monday's press conference, Smithee said authorities don't have any confirmation that a "potential second suspect" opened fire and all leads into who that person may be were being investigated.

"We've gotten multiple reports that there may have been another person with him, that they ran this way or they ran that way, but different people gave different versions, so we really don't know at this point," Smithee said.

The FBI was among numerous law enforcement agencies assisting Gilroy police, who were leading the investigation. Smithee said overnight the suspect or suspects appeared to have cut through a wire fence at a creek bordering the festival grounds to bypass heavy security to gain access.

Witnesses told CBS News the gunman appeared to be firing at random. Some witnesses said he suddenly appeared from behind a stage before beginning to shoot.

"It's just incredibly sad and disheartening that an event that does so much good for our community has to suffer from a tragedy like this," Smithee added.

The shooting happened on the last day of the annual three-day festival. It features food, cooking competitions and music and attracts more than 100,000 people, The Associated Press notes.

Gilroy, a city of 50,000 some 80 miles southeast of San Francisco, is known as "The Garlic Capital of the World."

Witness: "He just started shooting"

Cheryl Low and Candice Marquez were working at a vendor's booth at the festival. They told "CBS This Morning" on Monday that their bosses had been shot and are currently in the hospital, where they have both come out of surgery and are in stable condition.

They said the gunman had a high-powered rifle and did not appear to be specifically targeting people. "No, no. Just anybody. He was going back and forth," said Marquez.

"It was random," said Low. "He shot one shot, then he put the clip in, and he just started moving shooting back and forth, walking towards our tent because that's where most of the people were in that area, and he started just shooting."

6-year-old killed; mother and grandmother injured

Romero was at the garlic festival with his mother and grandmother, who were treated for gunshot wounds at the Santa Clara Valley Medical Center in San Jose. His mother was reportedly shot in the stomach and hand, and his grandmother in the leg.

CBS News' Janet Shamlian spoke with the boy's father outside the hospital Monday. He wasn't ready to say much, but did call it the worst day of his life.

Victim graduated from New York college in 2017

Irby studied biology at Keuka College, located about 55 miles southeast of Rochester, New York, and graduated in 2017, the school's president, Amy Storey, said in a statement. Irby was at the garlic festival with another graduate of the school who was not injured in the shooting, Storey said.

"Our hearts go out to Trevor's family and loved ones," Storey said. "We are shocked that this latest episode of senseless gun violence resulted in the loss of one of our recent graduates -- graduates in whom we place so much hope because of their potential to create a brighter tomorrow."

"Why are you doing this?"

The band Tin Man was doing an encore when gunfire erupted, CBS San Francisco reports.

Singer Jack van Breen said he saw a man wearing a green shirt and grayish handkerchief around his neck fire into the food area with what appeared to be an assault rifle.

Van Breen and other members of the band dove under the stage.

Van Breen told the station he heard someone shout, "Why are you doing this?" The person responded, "Because I'm really angry."

A festival attendee captured video of the band's set when the shooting began.

*WARNING: Possibly distressing footage*

Witnesses describe shooting

A young boy told CBS San Francisco what went through his mind:

Another witness described hearing what sounded like "a semi-automatic going off really close" when the shooting unfolded. "As soon as the gunfire started, everybody scattered and people were yelling for their kids," the witness told CBS San Francisco.

Another witness mistook the gunfire for a music act. "I thought it was, like, an opening act for the concert," he said.

Trump, candidates, lawmakers react to shooting

In Washington Monday morning, President Trump expressed his "deepest sadness and sorrow" for the victims' families during a legislation-signing ceremony in the White House Rose Garden. Mr. Trump called the shooting "horrific" and thanked law enforcement for their quick response.

"While families were spending time together at a local festival, a wicked murderer opened fire and killed three innocent citizens, including a young child," the president said. "We grieve for their families, and we ask that God will comfort them with his overflowing mercy and grace. We are praying for those who are recovering right now in the hospital."

Former Vice President Joe Biden, the front-runner for the 2020 Democratic presidential nomination, weighed in on Twitter.

Fellow 2020 Democratic presidential candidate Sen. Kamala Harris of California, who grew up in the East Bay and previously served as San Francisco district attorney, also tweeted about the shooting, calling it "simply horrific."

California Gov. Gavin Newsom echoed Harris' statement and said that the state "stands with the Gilroy community."

ATF and FBI responds to Gilroy shooting

The ATF office in San Francisco is responding to the reported shooting, according to a tweet Sunday night. The FBI is also assisting.

Gilroy police set up reunification services

The Gilroy Police Department have set up services meant to help reunite those who were at the Garlic Festival with their loved ones, including a phone number and reunification center at Gavilan College in parking lot B.