IRVING, Texas (CBSDFW.COM) – The woman who was mauled to death by her two pit bulls at an Irving animal hospital had to walk them outside herself because the dogs were too “aggressive” for staff do it, the hospital said in a statement.

Johana Villafane, 33, died Saturday after she was attacked by her two dogs at O’Connor Animal Hospital while in an outdoor area of the clinic. According to police and the hospital, staff members and first responders were unable to help her at first because the dogs were still near her.

Responding officers were forced to shoot and kill the dogs in order to take her to hospital, where she later died.

Villafane brought the two dogs to the hospital to be quarantined after an incident earlier this month where they bit someone.

“I examined the two dogs at the time of admission. The male pit bull terrier was friendly, but the female pit bull terrier seemed to be scared…,” said veterinarian James Kang. “The next morning, our staff could not walk them in the backyard due to the dogs’ aggressive behavior.”

According to the hospital, the dogs could only stay at the hospital if Villafane walked them. The hospital said the family went to the clinic twice a day for a week and walked the dogs without incident.

On Saturday, Villafane went to walk the dogs at 11 a.m., which is when the deadly mauling happened.

The hospital said it was busy with other patients and couldn’t hear any noises or screaming coming from the backyard. One of the receptionists eventually saw Villafane lying on the grass and called 911.

“The whole situation was traumatic, chaotic and emotional for everyone in our hospital staff, including myself. We are trying to overcome this tragic incident and move forward,” said Kang.