JACKSONVILLE, Fla. (AP) — The death of a 3-year-old boy whose body was found in an underground sewage tank has the mayor of Jacksonville, Florida, ordering safety reviews at hundreds of parks.

Jacksonville Mayor Lenny Curry said the "city is in mourning" over the death of Amari Harley, who went missing during a family outing at Bruce Park on Sunday. His body was found in the tank hours later.

A resident had complained to the city in January about "an uncovered hole with water and sewage trash" next to the park's restroom, noting that the park was used daily by children, the Florida Times-Union reported .

The mayor said the city made repairs the next day, and again the next month, and that city records showing monthly inspections through September found no more problems.

It is still not clear how Harley got into the tank. The city is investigating whether the lid was properly secured at the time.

"When all the facts are known, if mistakes were made, I will ensure there is accountability," Curry said.

Bruce Park is one of 76 in Jacksonville with septic systems for restrooms. The tanks are covered by lids made of fiberglass, metal or concrete, which are fastened with bolts, screws or latches.