After having been reported missing on Tuesday, Frisco mother Christine Woo was found dead at the Custer/121 Target parking lot Thursday evening alongside her three children, who were alive beside her body in their car.

“There is an active investigation and her cause of death is undetermined. The Collin County Medical Examiner’s Office will determine the cause of death,” Frisco Police Department Sgt. Jeff Inmom said in a Fox 4 News article. “We are conducting an investigation with the assistance of the McKinney Police Department to determine exactly what did happen.”

According to KDFW-TV, the children were severely dehydrated and CBS11 reported that there were no signs of trauma to Woo’s body. The Collin County medical examiner’s office still has not issued a cause of death.

“All three children were found alive inside of the vehicle and were transported to a nearby hospital for evaluation,” the Frisco Police Department said in a press release.

In a report filed by NBC5 Woo’s husband Brandon Woo said he called police Tuesday afternoon, after having seen her last on Monday morning, to report she was missing with five-year-old daughter Lauren Woo, three-year-old son Nathan Woo and one-year-old Leah Woo.

“She’s a loving mother, she’s like a lioness,” Woo said. “She would fight for her kids, she would never hurt her kids at all.”