The coroner's office identified the woman as 61-year-old Margerita Mojarro, of San Pedro. A close friend of the family, who is also their neighbor, confirmed to Eyewitness News that Mojarro was the mother of the bride.
The tree fell Saturday around 4:30 p.m. at Penn Park, killing Mojarro and critically injuring a 4-year-old girl, who suffered head trauma.
The family friend said the little girl is the bride's niece.
Mojarro's daughter had just gotten married and the wedding party had come to Penn Park to take photos. The group was posing for pictures when the tree suddenly uprooted and gave way, crashing down on those below. Around 20 people were trapped under the large eucalyptus tree's trunk and branches.
In addition to the fatality and the injuries suffered by the little girl, at least four others were hurt as well.
That little girl's mother spoke to Eyewitness News over the phone on Monday. She said her daughter is improving at the hospital and is moving her arms and legs.
Penn Park remained closed on Monday as the investigation continues. Meantime, Whittier officials say they want answers.
"We have a regular tree-maintenance program. We have a certified arborist on our staff that are managing our parks and our street trees, but at this point, we want to make sure we determine what caused this tree to go over," said Whittier City Manager Jeff Collier.
Though the cause of the collapse is still unknown, Collier said the weather may have played a role.
"We did have rain, which we haven't seen in quite some time. We have the drought conditions that have occurred out here, and we did have some heavy winds that occurred on Friday night," Collier said. "Those are all possible contributing factors, but we don't know, and we'll allow the arborist to make those determinations based upon the completion of the investigation."
According to Collier, a certified arborist was actually at the park on Saturday morning to check things out after the storm but did not notice any issues.
An arborist was expected at the scene of the incident on Monday to look into what caused the tree to collapse and also check the structural integrity of the rest of the trees in the park to ensure safety before the park reopens.