An 89-year-old woman has died from injuries that she sustained when two pit bulls attacked her and her 12-year-old grandson last week, authorities in Colorado said Monday. 

The attack happened on Wednesday in the backyard of a home in Golden, Colorado, which is about 15 miles outside Denver. The woman’s grandson, who was also seriously injured during the attack, has since been released from the hospital and is recovering, according to the Golden Police Department’s latest update. Neither the child nor his grandmother have been publicly named.

Police say that officers received a call reporting an animal bite around 3:30 p.m. on the afternoon of the attack. The call came from a neighbor’s house, where the child had fled to seek help. He was found bleeding when officers arrived, and they found an additional trail of blood leading to the residence where the two dogs were still attacking his grandmother in the backyard. 

Officers used tasers and less-lethal shotguns but weren’t able to separate the dogs from the victim until additional officers arrived.  

Police said the woman and her grandson knew the dogs, but did not provide additional details.

One of the two pit bulls was injured during the attack and euthanized at a veterinary hospital soon after it happened. The second was taken to an animal shelter following a veterinary evaluation, police said, and euthanized after its owner surrendered care to the facility. 

An investigation into the incident remains ongoing. One day after the attack, Golden Police said that authorities were working to verify whether the pit bulls involved were licensed and vaccinated in accordance with city protocols.