Tornadoes tore through a stretch of central United States on Sunday, killing at least 16 people and leaving behind a river of carnage in Arkansas and stretches of devastation in Oklahoma and Kansas. Even as emergency responders continue searching for people amid the destruction, additional twisters are forecast for Monday.

(UPDATE: Jason Samenow of the Capital Weather Gang is posting updates on the Monday tornadoes, with damage reported in Mississippi and areas of concern remaining in surrounding states.)

In Arkansas, reports of tornadoes touching down began on Sunday evening. A tornado that crossed Interstate 40 was reported to be half a mile wide, according to the National Weather Service. In the minutes that followed, 18-wheelers were overturned on the highway, homes ravaged, and the state’s Game and Fish Headquarters near Mayflower was destroyed.

It didn’t appear that a single tornado was responsible for the destruction stretching more than 80 miles, the National Weather Service said.

The impact was massive and widespread. Aerial footage captured by a drone showed the scope of the destruction:

And here’s footage from the ground, giving us a glimpse of just what people in the area were seeing:

The death toll in Arkansas stood at 14 as of Monday afternoon. Faulkner County reported 10 deaths, Pulaski County reported three fatalities and White County reported one death, according to the Arkansas Department of Emergency Management.

It was initially believed that 16 people were killed in Arkansas, but the death toll was reduced to 14 after it turned out that Pulaski County had double-counted fatalities, the office of Arkansas Gov. Mike Beebe (D) said. Still, Beebe’s office said the death toll is expected to rise.

In addition, at least one person was killed in Iowa and another in Oklahoma, the Associated Press is reporting.

And the danger isn’t over. The National Weather Service’s Storm Prediction Center warned that severe storms — “including strong tornadoes, damaging winds and very large hail” — are expected Monday and Monday night in states along the eastern and southern part of the country. The area with the greatest risk stretches from Kentucky and Tennessee to Mississippi and Alabama.

In addition, there’s still danger lingering into Tuesday and Wednesday:

President Obama offered condolences to the victims of this weekend’s tornadoes during a news conference in the Philippines:

The White House said Obama had directed FEMA Administrator Craig Fugate to travel to Arkansas to manage the federal response.

UPDATE: This story has been updated to reflect the changed death toll. Last update: 3:38 p.m.