GILLETTE, Wyo. (AP) — Plans to shoot off an enormous firework during a pyrotechnics convention worry some residents of a Wyoming community.

Pyrotechnics Guild International will hold its annual convention in Gillette in August.

One feature of the event will be setting off an enormous, mortar-style firework. The handmade shell measures 36 inches wide — as big as any featured in fireworks shows in the U.S.

Some locals worry the big boom will be too close to their homes. Guild President Paul Smith tells the Gillette News-Record his organization is scouting out different locations.

Guild guidelines call for spectators to be no closer than 100 feet for every inch of a shell's diameter, putting them at least 3,600 feet away from the site.