TAMPA, Fla. (AP) — A woman tried to build an explosive device inside a Walmart store in Florida, authorities said.

Emily Stallard was charged with attempted arson of a structure, fire bombing, contributing to the delinquency of a minor, child abuse and battery on an officer, the Hillsborough County Sheriff's office said.

A security guard at the store noticed Stallard opening unpaid items including flammable materials, projectiles and matches as she roamed through the store for more than an hour Saturday, according to an arrest report. She had a child with her in the store, police said.

The security guard called the sheriff's office and also notified a Florida Fish and Wildlife officer who happened to be in the store at the time. The two men stopped Stallard just before she lit a wick, according to the report.

Investigators said Stallard spit at deputies as she was being loaded into a patrol car.

“This woman had all the supplies she needed to cause mass destruction at her disposal. Had it not been for an alert off-duty law enforcement officer and watchful security staff at Walmart, she may have followed through with her plans to cause an explosion inside the store,” Sheriff Chad Chronister said in a news release.

Stallard remained in the Hillsborough County Jail on Tuesday. An attorney was not listed on jail records.