Complex sentence: Later reports on the outbreak indicated that by May 18, rumours were already circulating that Walkerton PUC water was the cause of the illness increasing numbers of residents were suffering and staff at the PUC had begun receiving calls enquiring as to the safety of town water.
Split into simpler sentences: Later reports on the outbreak indicated that by May 18, rumours were already circulating that Walkerton PUC water was the cause of the illness increasing numbers of residents were suffering. Staff at the PUC had also begun receiving calls enquiring as to the safety of town water.