A construction worker was killed early Thursday, March 10, after a large truck sunk into the mud, causing a deadly chain reaction.

The incident happened in Pinson, in east Jefferson County, around 6:50 a.m. The Jefferson County Sheriff’s Office said the worker was at a construction site on Brandi Circle, in the Innsbrooke subdivision.

“Upon arrival, it appeared that the supports of a concrete truck with a boom extension, sunk into the mud, causing the extension to swing around and strike a worker at the scene,” Sgt. Joni Money stated in a press release.

The man killed has not been identified but Money said he was 42 years old.

Detectives are conducting a full investigation into the incident.