McDONALD COUNTY, Mo. — Authorities said a semi-truck that was ablaze is the reason for the closing of I-49 Monday.

Currently, I-49 southbound remains closed and will be for an extended period of time, McDonald County authorities said.

The accident occurred around 1:00 PM Monday around Mile Marker 2.6. Authorities said the semi was carrying cardboard.

The exact cause remains under investigation.