An unidentified man was fatally struck by a school bus Wednesday evening in the city's Port Richmond section, police said.

There were no children on the bus when the man apparently made contact with the side of the bus and fell under the rear tires just after 5:15 p.m. on Allegheny Avenue at Aramingo Avenue, said Chief Inspector Scott Small.

The 53-year-old bus driver told police that the man, described as in his late 30s or early 40s, appeared to be staggering in the bicycle lane on Allegheny Avenue when the accident occurred.

The man was transported by medics to Hahnemann University Hospital, where he was pronounced dead at 5:49 p.m. The bus driver and another adult on board were not hurt.

The cause of the accident was under investigation.