NOT STOP HERE, EXTREME TEMPERATURES CAN BE HARD FOR BOTH HUMANS AND ANIMALS. COMING UP ADD 5:30, INPUT AND ADVICE FOR PET OWNERS. >>> A WOMAN BABYSITTING HER FRIENDS INFANT TWINS HAS BEEN CHARGED WITH KILLING ONE OF THE BOYS AND INJURING THE OTHER. HAPPENING THIS WEEKEND IN SHADYSIDE. >> NOW IN THE ALLEGHENY COUNTY JAIL, SHELLEY BORTZ IS THERE AND JOINS US WITH THE DETAILS. >> Reporter: NICOLE AS HE IS BEHIND BARS CHARGED WITH HOMICIDE AFTER POLICE SAY THAT SIX-WEEK-OLD LEON KATZ DIED WHILE IN HER CARE. >> I WOULD IMAGINE, JUST TERRIBLE, AND I FEEL SO SORRY FOR THE FAMILY. >> Reporter: AND UNIMAGINABLE CRIME, YET POLICE SAY THAT IT HAPPENED IN THIS SHADYSIDE NEIGHBORHOOD. SIX-WEEK-OLD TWIN BOYS , ONE FIELD, THE OTHER INJURED AT THE HANDS OF THEIR BABYSITTER. >> THEY ARE SO INNOCENT THEY DIDN'T ASK FOR THIS, AND THEY WERE HELPLESS AND YOU JUST DON'T UNDERSTAND. WHY SOMEONE WOULD HAVE THIS IN THEIR HEART, IT IS A TERRIBLE FEELING. WHAT WOULD PRECIPITATE SOMETHING LIKE THIS? I CANNOT IMAGINE. >> Reporter: POLICE WERE CALLED TO THIS APARTMENT BUILDING ON WALNUT STREET SATURDAY NIGHT, FOR A REPORT THAT A BABY HAD FALLEN FROM A BOUNCER. THE 911 CALLER WAS IDENTIFIED AS 29-YEAR-OLD NICOLE VIRZI. A FRIEND OF THE BABY'S PARENTS, WHO WAS VISITING FROM SAN DIEGO. SHE TOLD INVESTIGATORS, SIX-WEEK-OLD LEON KATZ, FELL FROM THE BOUNCER WHEN SHE LEFT THE ROOM TO GET HIM A BOTTLE. RUSHED TO UPMC CHILDREN'S HOSPITAL, WHERE HE LATER DIED FROM BLUNT FORCE TRAUMA TO THE HEAD, THAT CAUSED A SKULL FRACTURE. DOCTORS WHO TREATED KATZ SAID THAT HIS INJURIES WERE NOT ACCIDENTAL. NICOLE VIRZI'S ATTORNEY DISAGREES. >> OUR CLIENT WAS ARRESTED QUICKLY INTO THE ROLE OF HAVING TO BABYSIT A SMALL CHILD AND AN ACCIDENT OCCURRED AND THE CHILD DIED AND UNFORTUNATELY, ACCIDENTS DO HAPPEN AND IT IS A SAD THING AND AN AWFUL THING. IT DOESN'T MEAN THAT SOMEONE IS CULPABLE. >> Reporter: ACCORDING TO THE CRIMINAL COMPLAINT, THE REASON THAT NICOLE VIRZI WAS WATCHING LEON KATZ ON SATURDAY NIGHT WAS BECAUSE HIS PARENTS HAD TO RUSH HIS TWIN BROTHER TO THE HOSPITAL, FOR AN INJURY TO HIS AREA AFTER BEING IN NICOLE VIRZI'S CARE EARLIER THAT DAY. LEON KATZ'S TWIN BROTHER WAS FOUND TO HAVE SCRATCHES, BRUISES AND SWELLING. >> I WOULD ASK THE PUBLIC TO ALWAYS LISTEN TO THE FACTS AND NOT JUMP TO CONCLUSIONS AND ALLOW THE FACTS TO COME OUT AS APPROPRIATE. >> Reporter: NICOLE VIRZI CHARGED WITH HOMICIDE, AGGRAVATED ASSAULT, AND ENDA