1 September 2021

George County: a drone video of the site of a fatal landslide triggered by Hurricane Ida

Posted by Dave Petley

George County: a drone video of the site of a fatal landslide triggered by Hurricane Ida

The landfall of Hurricane Ida across the southern USA earlier this week caused high levels of rainfall, inducing flooding and landslides.  In terms of mass movements, one of the most significant events occurred in the Benndale community in George County in Mississippi, where a substantial failure destroyed a section of MS26.  The landslide had substantial consequences –  it killed two people and injured a further 10, three of them critically.

The SunHerald has a detailed article about the event,  and has published a drone video of the aftermath.  The site is quite interesting, as this overhead view shows:

The George County landslide

The fatal landslide in George County, Mississippi. Image taken from a drone video posted by the SunHerald.  Drone video by Travis Long.

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The view below, also from the drone video, provides an understanding of the form of the landslide:

An oblique view of the fatal landslide in George County

An oblique view of the fatal landslide in George County, Mississippi. Image taken from a drone video posted by the SunHerald. Drone video by Travis Long.

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The SunHerald article provides some information about the landslide:-

“It is a slide, which means the ground under the roadway and embankment was super-saturated and we can tell right now that’s what caused the slide,” said Kelly Castleberry, district engineer for the Mississippi Department of Transportation. “The ground liquified and it spread several hundred feet to the south.”

Castleberry said the drone footage shows a path created by groundwater, which is beneath the earth, not surface water…He said groundwater from all the rain, a water-line leak, or both, could have caused the collapse that killed two people and injured 10, three of them critically. MDOT is investigating the cause and will have an update when more information is available, Castleberry said.

The road appears to be on embankment, which has failed.