An 84-year-old man walking across Merrick Road in Rockville Centre in a crosswalk Thursday was struck and killed by a tractor trailer, Nassau County police said.

Police said the victim, Juan Galdos of Rockville Centre, was pronounced dead at the scene.

advertisement | advertise on newsday

The accident occurred at about 11:45 a.m., and police closed Merrick Road in both directions between Cumberland Street and North Long Beach Road for nearly four hours to investigate.

Detectives said the victim was crossing Merrick Road from north to south in a marked crosswalk at Oceanside Road when he was hit by a 2003 Peterbilt tractor trailer driven by a 59-year-old man.

The tractor trailer was eastbound in the right lane of Merrick Road at Oceanside Road when it struck Galdos, police said.

Safety checks were performed on the tractor trailer at the scene, police said, and the investigation is ongoing.

advertisement | advertise on newsday

Detectives said there appears to be no criminality.