In 1999, 30 people died from infection by Legionella pneumophila bacteria after visiting a flower exhibition in Bovenkarspel, The Netherlands. This event prompted Kemira Agro Rozenburg to sample its cooling tower water at regular intervals for the presence of the Legionella bacteria. The results were consistently negative until the spring of 2000 when a sudden outbreak of the bacteria was detected. Safety measures were implemented immediately, the cause of the outbreak was discovered, and measures were subsequently taken to prevent a reoccurrence.