A devastating, mile-wide tornado touched down near Oklahoma City on Monday, decimating homes, businesses and schools in the suburb of Moore. There were no immediate reports of fatalities or injuries, as emergency personnel urged people to remain off the roads so rescue workers could reach people trapped in the rubble.

“This is war zone terrible,” Jon Welsh, a helicopter pilot for KFOR-TV who lives in Moore, said while surveying the damage from the air. “This school is completely gone.”

The funnel cloud could be seen for miles, creating a debris field several miles wide. According to the National Weather Service in Norman, Okla., the tornado was on the ground for approximately 40 minutes, and a tornado warning was in effect for 16 minutes before twister developed.

Weather officials estimated the strength of the tornado to be an F4 or F5, the highest intensity rating on the Fujita scale.

Tornado damage seen in Moore, Okla., May 20, 2013. (KFOR-TV)

A host on KFOR called Monday’s storm “the worst tornado damagewise in the history of the world.”

The 106-acre Orr Family Farm was completely destroyed, killing between 75 and 100 horses, KFOR said.

Another tornado was reported on the ground west of Meeker, north of Shawnee, on Monday.

The Oklahoma House of Representatives canceled its afternoon sessions so lawmakers and staffers could take shelter, the Associated Press said.

The tornado comes a day after powerful storms ripped through the center of the country, spawning at least a dozen tornadoes, killing two people and causing extensive damage from Georgia to Minnesota.

According to the Oklahoma state medical examiner, the two victims in Sunday’s storms—Glen Irish, 79, and Billy Hutchinson, 76—were from hard-hit Shawnee. At least 39 other people were injured on Sunday, Oklahoma emergency management director Albert Ashwood said.