WESTFIELD, Ind. (AP) — Police in suburban Indianapolis say an orchestra pit cover that collapsed during a high school musical production, sending several students falling, had been replaced earlier this year and wasn’t properly designed.

The Westfield Police Department on Tuesday announced the findings of its investigation into the April 23 collapse that injured 17 students.

Capt. Charles Hollowell says a school employee purchased building materials and constructed an orchestra pit lid to replace the one that had been removed in January. The replacement lid lacked the metal supports that the original had.

Hollowell says no charges will be filed.

Supt. Mark Keen says all but one of the injured students has returned to class at Westfield High School, about 20 miles north of Indianapolis. The school plans its own investigation.