A Pennsylvania daycare operator could face criminal charges for leaving a neighbor's toddler in her van, where he died of hyperthermia.

The death at Fairy Tales Daycare in Penndel is being investigated by Bucks County District Attorney Michelle Henry, The Trentonian in Trenton, N.J., reported.

Henry said Rimma Shvartsman, a co-owner of the daycare, picked up Daniel Slutsky, 2, Wednesday morning. Shvartsman lives near the boy's parents. When Shvartsman arrived at the daycare, she apparently forgot the boy was in her van strapped in a child's car seat.

She found him there unresponsive at about 4:30 p.m.

Henry said the temperature inside the van could have topped 100 degrees on a day when the temperature outside was in the 80s. An autopsy confirmed Daniel was killed by hyperthermia.

Shvartsman had been caring for Daniel at the daycare center three days a week for months, usually driving him there.