HAMBURG, Iowa (AP) – Crews are trying to build up a protective wall to keep floodwaters from reaching Hamburg, after the swollen Missouri River punched a massive hole in the main levee.

The river ruptured two levees in northwest Missouri on Monday, sending torrents of water over rural farmland toward Hamburg, and a Missouri resort community.

Water spilling through a nearly 300-foot hole in a levee a few miles from Hamburg is expected to reach the town by Tuesday. Floodwaters could top a secondary levee built to protect the town by Wednesday.

The Army Corps of Engineers says crews are working to increase the wall’s height by 3 feet. If it breaks, parts of Hamburg could be under as much as 10 feet of standing water.