A pedestrian and a man on a stolen motorcycle were killed in separate crashes Sunday in Philadelphia.

The first deadly crash happened shortly after 1:30 a.m., when someone driving  a 2000 white Chevrolet Impala north on the 7300 block of Castor Avenue in Rhawnhurst struck a man who was in a crosswalk, authorities said.

Philadelphia police on Monday identified the victim as 51-year-old Nilton Monteir, of the city's Mayfair section. Monteir was taken to Aria Health's Torresdale Hospital, where he was pronounced dead at 4:07 a.m.

The Impala fled and was found unoccupied about two blocks away, at Shelmire Avenue and Horrocks Street, police said.

The driver had not been identified or located as of Monday morning.

Then, about 4:10 p.m., a 40-year-old woman driving a 2006 Kia Optima made an illegal left turn from the 400 block of East Roosevelt Boulevard onto C Street, colliding with a 2013 Kawasaki motorcycle that was traveling at a high speed, police said.

The motorcyclist, a 27-year-old man whose name was not released, was ejected from the motorcycle. He was not wearing a helmet, police said.

The man was taken to Albert Einstein Medical Center, where he died at 7:47 p.m.

The motorcycle, which police said was reported stolen on July 21, caught fire after the crash.

The Optima driver, who also was not identified, received medical treatment at the scene. No charges have been filed as of Monday.

Both crashes remain under investigation.