21. Icebreakers were built in order to maintain the river free of ice jam , east of Montr�al. 22. Fortunately for Columbus, an ice jam destroyed the Lost Creek bridge in the spring of 1881. 23. In the early season ( June ), boaters may encounter ice jams anywhere along the river. 24. Massive ice jams clogged the Missouri River and when they broke the downstream areas were ravaged. 25. These ice jams can cause considerable damage to structures along the riverbanks and on the floodplain. 26. On Wednesday, demolition experts broke up an ice jam 65 kilometers ( 40 miles ) upstream. 27. In March 1901, flooding and ice jams severely damaged a number of bridges over Mahantango Creek. 28. Workers north of Fargo returned to work Tuesday trying to break up a mile-long ice jam . 29. In 1961, a severe ice jam threatened to destroy the bridge, but the jam was successfully dynamited. 30. On the other hand, sudden releases from ice jams that abruptly dislodge can send floodwaters rushing downstream.
