(Updates with explosives detonated, details, quotes)
By Mary Wisniewski
BIRDS POINT, Mo., May 2 (Reuters) - Flames shot up and a loud boom was heard on Monday as the U.S. government blew a hole in a Mississippi River flood levee in a bid to save several towns in Illinois and Kentucky from being inundated.
A witness said water began to pour out of the hole after the explosion and is expected to eventually flood some 130,000 acres (52,600 hectares) of farmland in Missouri in order to spare the towns.
The deliberate destruction of the levee after nightfall and during a driving rain, ended days of debate and legal wrangling over how to cope with the rising flood waters of the Mississippi and nearby Ohio river.
Carlin Bennett, a commissioner in the rural Missouri county that will bear the brunt of the flooding, estimated the U.S. government action will cause $1 billion in property damage.
"It's going to be like a mini tsunami through here," he said. "We can't really imagine it right now."
The state of Missouri petitioned all the way to the Supreme Court in an unsuccessful attempt to stop the action. The states of Illinois and Kentucky opposed Missouri, joining the U.S. Army Corps of Engineers in pushing for destruction of the levee in hopes of saving several towns in their states.
One town the Corps hopes to save is Cairo, an historic community of 2,800 people located at the confluence of the Ohio and Mississippi. The town was largely empty after a mandatory evacuation on Sunday.
Located at the southern tip of Illinois between Missouri and Kentucky, Cairo was an important destination for runaway slaves during the U.S. Civil War. Both Missouri and Kentucky were slave states and Illinois was a free state.
"I'm very relieved," said James Wilson, spokesman for Cairo mayor Judson Childs. "I wish they could have done it three days earlier." He said some people in the nearby town of Olive Branch already have lost their homes to flooding.
Witnesses near the spot where the levee was breached on Monday said the flood waters were already so high that it was hard to tell where the Mississippi River usually ends.
Trees were standing in water along the banks and water swelled along the sides of the highway. Flood waters covered farm fields and rain was relentless all day, with a cold wind.
On top of the levee, reporters in TV trucks waited along with army personnel. Across already flooded fields could be seen the lights of U.S. Army corps barges, where the explosives were detonated to blow up the levee. Flood water covered the road entering the town of Cairo. (Additional reporting by Miriam Moynihan; writing by James B. Kelleher)