Fond du Lac fire investigators say all three fires over the weekend were started by improperly discarded materials including fireworks. Within a two hour time span Saturday night and Sunday morning fires damaged a garage on New Haven Avenue, destroyed a dumpster and damaged the vinyl siding of the Fond du Lac Townhomes on South Brooke Street and destroyed a garbage container on North Peters Avenue. Assistant chief Jim Knowles says the townhouse dumpster fire could have been started by either fireworks, charcoal ashes or smoking materials. Knowles says always place used fireworks in a pail of water before tossing them in the garbage. Knowles says even sparklers can start a garbage container on fire if not cooled off in water first. Nobody was injured in any of the fires.