As parents of kindergarten students at St. Bernadette of Lourdes Catholic elementary school in Drexel Hill waited for their little ones to be released Thursday afternoon, a few of them made a chilling discovery in the school's parking lot — a plastic bag containing 29 smaller bags of white powder, according to police.

The parents grabbed the bag and turned it over to the principal, who in turn called authorities to the school at Bond and Turner Avenues around 12:43 p.m., said police Superintendent Michael Chitwood.

In total, there were 41 smaller bags inside the large one, including 12 empty bags that had red-and-black skulls with wings stamped on them, according to police. The 29 bags that were full of white powder were free of marks, Chitwood said.

"We initially suspected it to be heroin but it later field tested back as pure fentanyl," he said. "Thank God the adults found it. Imagine if one of those kindergartners got a hold of the fentanyl."

Fentanyl is a synthetic opioid that is anywhere from 50 to 100 times stronger than morphine. Last year in Philadelphia, overdose deaths where fentanyl was present more than doubled from 184 to 413, according to the city's Department of Public Health.

Chitwood said he believes the bag was accidentally dropped.

"And I would guarantee it's got to be a parent or guardian of one of the kids," he said. "Our investigation is continuing, but we know it has nothing to do with the school and nothing to do with the kids."

In a letter sent home with students, school Principal Joanne Montie said at no time were any children in danger and that going forward, the school's facilities manager will do a thorough check of the school grounds each morning.