(AP Photo/Jeff Roberson)
As Supreme Court Justice Samuel Alito issued his ruling, struggling Cairo near the confluence of Ohio and Mississippi rivers resembled a ghost town.
Illinois National Guard troops went door to door with law enforcers to enforce the mayor's "mandatory" evacuation order the previous night.
Alito did not comment in denying Missouri's request to block the corps' plan. Alito handles emergency requests from Missouri and other states in the 8th Circuit in the Midwest.
Maj. Gen. Michael Walsh, the corps officer in charge of deciding whether to breach the levee, ordered field crews to move barges to the Missouri side of the river and begin loading pipes in the levee with explosives in anticipation of blowing up a two-mile section just downriver from Cairo. He stressed that the decision to do so has not been made.
Missouri Attorney General Chris Koster, whose bid to derail the corps' plan in recent days included failed requests to a federal district judge and an appellate court, took the case to the Supreme Court, noting "it is the responsibility of this office to pursue every possible avenue of legal review."
Koster's office did not immediately return a call seeking comment after the court's ruling.
Corps officials are monitoring water levels and haven't decided whether to go through with the blast to blunt the rise of the Ohio, which on Sunday afternoon had risen to 59.93 feet at Cairo -- eclipsing the 1937 record there of 59.5 feet. The river was expected to crest Tuesday at 61.5 feet and stay there for days, raising the corps' concerns about the lingering strain water that high could put on levees. Cairo's floodwall can handle 64 feet.
After touring the levee with Walsh on Sunday, Missouri Gov. Jay Nixon declined to discuss the litigation. He said he understood the difficulty in Walsh's decision and was assured that if the levee is blown apart, it would be done safely.
"This is a dramatic, once or twice in a lifetime kind of occurrence," for the region, Nixon said, noting the record water levels. "We understand the general and his team have difficult decisions to make."