(CBS) — Oak Lawn Police say there was no foul play involved in nails found protruding from slides on a playground last month, according to a press release from the village.

10 one-and-a-half inch drywall nails were found protruding from two of the five slides at Oak Lawn’s Memorial Park They were discovered and removed before anyone was hurt.

Police initially suspected that someone embedded the nails in the slides with the intent of hurting someone. Following a police investigation that involved cutting away parts of the slides, it was determined that, “The nails were part of the manufacturing or installation process of the playground equipment,”

The Oak Lawn Park District says they are investigating whether the nails were the result of a design flaw or an installation error.