A 56-year-old Lafayette man walking behind a dump truck was killed Monday when the truck hit him as it was backing up, officials said.

Douglas W. Perroncel walked behind the truck on a lot in the 2200 block of Cameron Street at around 3:30 p.m. and was hit by the bumper, Lafayette Police Cpl. Nicole Benoit said.

Investigators do not know why Perroncel walked behind the truck, Benoit said in a news release.

Perroncel was transported to a hospital and pronounced dead.

Police have not issued citations in a case that remains open.