The California parents of twin girls are having sleepless nights after one died and the other is in critical condition following a drowning incident.

17-month-old Makayla and Maya fell into a backyard pool on April 29 ago after pushing the screen out of their window, reported KTLA.

The girls' mother, Erika Alvarado, said she and their father, Jeremiah Edwards, had dozed off for a few minutes while the toddlers played in the living room. When Alvarado awoke, her daughters were gone.

The parents immediately ran to the pool where she only saw one of her daughters.

"Jumped in, grabbed her," Alvarado told KTLA. "I was working on Maya. He saw Makayla in the shallow end."

They called 911 and performed CPR; however, they still could not feel a pulse on either girl.

At the same time, a Riverside County sheriff's corporal was patrolling the neighborhood and heard shouting.

"I heard someone screaming from inside the house," Rafael Victoria told KESQ in an interview last Monday.

Victorio said he and other first responders also performed CPR on the children until paramedics arrived. Soon after, the Riverside County Fire Department transported the girls to a local hospital.

They had extensive brain damage and were both medically sedated, Alvarado said.

On May 12, the parents received the best and worst news of their life: Makayla woke up, while Maya was taken off life-support. Her organs have been donated, including her heart, which was donated to a baby who needed a transplant, Edwards told KTLA.

Makayla still remains in critical condition.

"We're not able to fully grieve because we have to be strong for Makayla. She's here and she's fighting," Edwards told KTLA.

The family set up a GoFundMe to help pay medical bills. The campaign has raised more than $32,000 as of early Monday evening.