NAPERVILLE, Ill. (AP) — Officials in the Chicago suburb of Naperville say repairs to a 160-foot-tall tower that houses a carillon could cost $1.6 million to about $3.8 million.

An assessment released Thursday of Moser Tower found that the tower's structural steel is beginning to corrode, its precast concrete is cracking and the concrete's mortar joints are facing deterioration. Officials say repairs will be needed in the coming years.

The tower houses the Millennium Carillon. The multi-million dollar project was built to commemorate the new millennium and was completed in 2007. The assessment noted that changing temperatures make the steel expand and contract, resulting in cracks.

The tower's original plan called for it to be enclosed in glass to protect it from the elements, but that was eliminated for financial reasons.