Both children were found unconscious at the bottom of a neighbor's pool.
Wednesday, Sheriff Eric Watson said no foul play was suspected, but the incident was being investigated as a crime as standard procedure.
Channel 3 learned Thursday the boy's sister was showing signs of improvement while at Children's Hospital.
No word on funeral arrangements.
Stay with WRCBtv.com for update to this story.
PREVIOUS STORY: Two children nearly drowned Wednesday evening, they were found unresponsive at the bottom of a neighbor's swimming pool in Bradley County.
Now the siblings are recovering at Children’s Hospital in Chattanooga.
Kevin Key lives next door to where the accident happened he describes the tense moments when his neighbor called for help. "He was just screaming bloody murder and crying, like he was in shock, he couldn't even move," Key said.
Key jumped the fence and assisted the father trying to save his kids.
"My mom went outside and heard screaming somebody help me help me and so that's when I ran out I ran next-door and then I saw the father with the little girl in the pool I tried to help the best I could everybody was just screaming and crying,” Key described.
Sheriff Eric Watson said, two siblings, a 7-year-old, and a 9-year-old, were found unconscious in their neighbor's in-ground pool.
“It's one of those true situations you don't want to find yourself in. Especially when it comes to two kids,” Sheriff Watson said.
Medics worked nonstop giving them CPR before they were eventually taken to Children’s Hospital where they are listed in critical condition. Sheriff Watson tells Channel 3 the little girl is now responding when spoken to, and her brother has started making small movements as well.
Now the family and tight knit community is praying for a safe recovery.
"It's not something you would want to see happen whatsoever to your own kids someone else's kids, it just plays in your head over and over again,” Key said.
Investigators say this accident does not appear to be suspicious. Neighbors say the pool is not properly secured and could have prevented this accident.
“If you really don't have your gates close or your pool is closed and you have little kids running around it's severely dangerous in case someone falls in and they're not supervised and something happens like last night,” Key added.
Details surrounding the kids' supervision at the time are still unclear.
Both are students at Hopewell Elementary, school officials say counselors were on hand for students and faculty.
PREVIOUS UPDATE: At last update, the children were still in critical condition, but are showing signs of improvement.
Sheriff Watson tells Channel 3 the little girl is now responding when spoken to, and her brother has started making small movements.
Bradley County Schools are making counselors available to students and teachers at the schools.
PREVIOUS STORY: Two children nearly drowned in Bradley County Wednesday night. The siblings, ages 7 and 9, were found unresponsive at the bottom of a neighbor's swimming pool around 5:00pm.
First responders worked nonstop giving the children CPR, but their efforts on the scene were not successful.
"As soon as they discovered the bodies, they didn't let up. All the way to the hospital," said Sheriff Eric Watson. "They did an excellent job."
According to Watson, a neighbor called 911. He said the siblings were later revived at Tennova Hospital, and were then transferred to Children's Hospital at Erlanger in critical condition.
One was flown by LifeForce, the other was transported by ambulance.
Watson said their parents were notified, and were with them at the hospital.
While investigators do not suspect any foul play, they said they treat the scene as a crime until proven otherwise. The details surrounding the kids' supervision at the time are still unclear.
The Sheriff is asking for the community's prayers.
"Thanksgiving is coming up. The holidays are coming up. Really, really keep this family in your prayers," said Watson. "They need your support. They need the community's support."
"We don't want to see two young kids die, due to these circumstances. We are praying, praying, praying."
The children are students at Hopewell Elementary School, where counselors will be on hand for classmates in the morning.
UPDATE: Sheriff Watson tells me the little girl is now responding when spoken to, and her brother is beginning to have movement. @WRCB