On New Year's Eve 1986 an arson fire started by employees in a labor dispute with management of the Dupont Plaza in San Juan, Puerto Rico killed 97 hotel guests and gamblers and injured hundreds more. Chips from the Dupont Plaza are frequently found with fire damage. See more about the fire on the Museum of Gaming History "This Week in Gaming History".
This Week in Gaming History
http://www.caribbeanchipguide.com/mogh_history.php