MONTEREY PARK, Calif. (KABC) -- One of the victims injured in a mass shooting at a Monterey Park dance studio has died from their injuries, raising the death toll to 11. Authorities are still trying to determine a motive for the slayings that left the community in shock.
Four victims of the shooting were being treated at LAC+USC Medical. On Monday, officials confirmed that one of those patients died.
"Unfortunately, despite our best efforts, we are saddened to share that one of the victims has succumbed to their extensive injuries," the hospital said in a statement. "We want to express our deepest sympathies to their families and loved ones."
"Of the remaining victims receiving care at LAC+USC Medical Center, one remains in serious condition. The remaining two patients are recovering."
County Supervisor Janice Hahn said it was the deadliest mass shooting in L.A. County.
This comes as authorities continue to investigate a motive for the gunman, Huu Can Tran. The 72-year-old was found dead from an apparent self-inflicted gunshot wound in a van in Torrance Sunday, the end of an hours-long manhunt for the shooter.
Investigators searched Tran's Hemet mobile home in a senior community Sunday night. L.A. County Sheriff Robert Luna said in an afternoon news conference Monday that investigators found a .308-caliber rifle, hundreds of rounds of .308-caliber and 9mm ammunition and "items that lead us to believe the suspect was manufacturing homemade firearm suppressors," or silencers.
Luna said 42 shell casings and a large-capacity magazine were recovered inside the Star Ballet Dance Studio, where the shooting occurred Saturday night.
Inside the cargo van, clothing Tran wore during the shooting was found.
Luna said the firearm wrestled away from the suspect at the dance hall in Alhambra was a 9 mm semi-automatic MAC-10 assault weapon, and that an additional handgun was recovered in the suspect's van.
Luna said the suspect had a "limited" criminal history: an arrest in 1990 for unlawful possession of a firearm.
Investigators are looking into the possibility that domestic violence may have played a part in Saturday's mass shooting.
On Sunday, after a daylong manhunt, police located Tran's vehicle along a road in Torrance, about 30 miles southwest of Monterey Park. As police pulled behind the van in a marked patrol car, the vehicle entered a shopping center parking lot. When officers exited their patrol car to approach the van, they heard one gunshot coming from inside the vehicle. The officers found Tran dead from a self-inflicted gunshot wound inside the van, which had a stolen license plate, according to authorities.
Tran used the van to flee after attempting to attack a second dance hall in Alhambra called the Lai Lai Ballroom, authorities said.
Brandon Tsay was in the lobby at the time, and he told ABC's "Good Morning America" that he thought he was going to die.
"Something came over me. I realized I needed to get the weapon away from him, I needed to take this weapon, disarm him or else everybody would have died," Tsay said. "When I got the courage, I lunged at him with both my hands, grabbed the weapon and we had a struggle."
Once Tsay seized the gun, he pointed it at the man and shouted: "Get the hell out of here, I'll shoot, get away, go!"
The assailant paused, but then headed back to his van, and Tsay called the police, the gun still in his hand.
Tsay did not know it at the time but would later learn that this same man had allegedly opened fire at Star Ballroom Dance Studio in nearby Monterey Park about 20 minutes earlier, killing at least 11 people and wounding 9 others.
Officials did not disclose any information about the 11th fatality, but all except one of the others were 60 or older, according to information released Monday by the Los Angeles coroner's office providing the first identifications.
My Nhan, 65, Lilian Li, 63, and Xiujuan Yu, 57, were the three women named. Two other women were in their 60s, and one was in her 70s. Valentino Alvero, 68, was the only man identified. Three men in their 70s and one in his 60s were also killed. Friends identified one of the men killed as dance instructor Ming Wei Ma.
Records indicate Tran worked as a professional trucker for at least 20 years, for a brief time running his own trucking company.
He served as CEO of a business based in San Gabriel called Tran's Trucking, Inc. But it didn't stay in business long. Records indicate the business was formed in 2002 but dissolved in 2004.
WATCH: Gov. Gavin Newsom calls guns 'No. 1 killer' after Monterey Park shooting
Tran's former wife, who asked not to be named, told CNN she met him about 20 years ago at Star Ballroom. Tran introduced himself at a dance and offered her free lessons. They married soon after that.
She said Tran had a short temper, though he was not violent. If she made a mistake dancing, he would get upset because he thought it made him look bad, she recalled.
Court records indicate Tran filed for divorce in 2005.
Tran was an immigrant from China, according to documentation on his marriage license shown to CNN.
A former tenant and longtime acquaintance of Tran told ABC News that he was a regular at the dance studios in Monterey Park and Alhambra.
Hemet police say Tran visited the department lobby on Jan. 7 and 9 of this year. He made allegations about fraud, theft and poisoning involving his family in the Los Angeles area 10 to 20 years ago, the department said. He said he would return with documentation proving his allegations but he never showed up again.
The massacre in Monterey Park was the nation's fifth mass killing this month. It was also the deadliest attack since May 24, when 21 people were killed in an elementary school in Uvalde, Texas.
The shooting happened in the heart of its downtown where red lanterns decorated the streets for the Lunar New Year festivities. The celebration in Monterey Park is one of California's largest. Two days of festivities, which have been attended by as many as 100,000 people in past years, were planned. But officials canceled Sunday's events following the shooting.
ABC News and the Associated Press contributed to this report.