(CBS) — Police in West Chicago are asking residents to be on the lookout for a thief — a thief with an eye on the city’s streets.

CBS 2’s Mike Puccinelli explains.

Since late June, someone has been picking up the 60-pound sewer grates along city streets, authorities say. More than 30 have been taken.

Investigators believe the grates are being sold to out-of-town scrappers.

“They cost the city in excess of $80 apiece,” West Chicago Police Cmdr. Eric Shipman says.

But for neighbor Rose Flores, what’s more concerning is the fear that a little kid could end up in the bottom of one of the holes.

“They’re small and they fit in there,” she says.

Cmdr. Shipman agrees.

“It’s large enough that a kid could easily fall in there and get hurt, if not a small child go all the way down,” he says.

The holes have been popping up all over. Some of the thefts have even taken place in broad daylight.

“They’ll take anywhere from four to eight of them at one click and then they take off,” Shipman says.

Police say a pickup truck has been spotted near the crime scenes.

Until the person is caught, neighbors say they’ll be on alert.

So far, no one has been injured because of the thefts. But police are worried that could change if a person drives, rides or stumbles into one of the holes.

Crimestoppers is offering a $1,000 reward for anyone with information leading to an arrest.