The Blackwater Massacre was an infamous and bloody shootout between the Van der Linde gang, Blackwater Police Department, The Pinkerton Detective Agency, and famous gunslinger Landon Ricketts. According to most accounts the massacre started when the Van der Lindes were robbing a ferry which was carrying $150,000 of bank money but, the heist suddenly Pinkertons swarmed the area, along with the police, forcing the gang to flee the ferry and start the gunfight that would lead to 37 deaths including 3 members of the Van der Lines, numerous Pinkertons and Blackwater policemen, and a young woman named Heidi McCourt. The three members who died were brothers Mac and Davey Callander (Mac was unable to rejoin the fleeing gang and was later captured then interrogated before dying, Davey managed to make it with the gang but would pass from his wounds), and Jenny Kirk (who too made it with the gang but passed away).
This event is seen by many historians as the beginning of the end for the Van der Linde gang as the massacre forced them to flee Blackwater and keep moving from camp to camp before most of the gang die and split up later on in the year.