Let's set the scene. Its April 23 and a very cold night in the North Woods of Wisconsin. The year is 1934. Coming down the lane(behind me) is the famous G-Man, Melvin Purvis, along with several other Feds and local cops. They are approaching the Little Bohemia Lodge near Manitowish.
As the Feds reconnoiter looking for their targets and a good place to hide and wait, out of the bar come three men getting into a car and leaving. The Feds, yelling "stop" and "police", are ignored, the revelers can't hear them over the radio. The G-Men, fearing they were under attack, shoot up the car killing the driver, a CCC worker, wounding the other two.
Upstairs, John Dillinger and gang hear the commotion and commence firing down on the Feds. In the confusion, the Feds scrambling for cover, Dillinger makes his escape. Its not quite over yet, though. As the Feds mill around the scene, Baby Face Nelson arrives and confronts some of the agents killing one and wounding others. He flees and makes good his escape as well. The FBI is held to ridicule and embarrassed. Some lessons have been learned at heavy cost. Purvis will later be at the Biograph Theater in Chicago when they finally get Dillinger.
The owners then and ever since then have preserved the bullet holes inside the place as curios of that age and night.