ROCHESTER, N.Y. (WROC) — The Tim Hortons in Rochester where a three-year-old boy died will remain closed until further notice, according to a sign posted on the doors.

The boy died after falling into a grease trap behind the eatery, on Rochester’s east side.

Police responded around 11 a.m. Monday after the boy’s mother reported the child was missing. A witness who discovered the boy attempted to give him CPR at the scene. The boy was then transported to the hospital, and pronounced dead.

Police were seen interviewing Tim Hortons employees and consoling a woman who was crying.

Grease traps are plumbing systems that must be located outside any building with the “capacity to serve group meals,” including restaurants, according to Monroe County code. The main component of a grease trap is a storage tank, designed to prevent fats, oils, and grease from pan-cleaning and food production out of the sanitary sewer systems.

The grease trap at the University Avenue Tim Hortons location is located in an open area in the back of the restaurant. Police say the lid to the grease trap’s tank was not only made of plastic, but was left unsecured over the 2-3 feet diameter of the trap. They say the boy must have stepped on the unsecured lid, causing it to open up, and trap him below.