Two men were killed and a police officer was injured in separate traffic accidents overnight in Chicago, authorities said.

In Rogers Park, a man identified as Michael Schaefer, 34, was struck by a cab in the 6800 block of North Sheridan Road and declared dead at St. Francis Hospital in Evanston at 4:20 a.m., according to the Cook County medical examiner's office. Schaefer lived a few blocks west, in the 6700 block of North Glenwood Avenue, according to the medical examiner's office.

The man was struck by a southbound taxi cab after walking into traffic near Sheridan and Pratt Boulevard just before 4 a.m. Thursday, police said.

The cab was believed to have had a green light when the pedestrian stepped out into traffic, said Chicago Police News Affairs Officer Jose Estrada. The cab driver remained at the scene after the accident, and was issued a citation for striking a pedestrian in the roadway. The Major Accident Investigation Unit was handling the crash.

In the second fatal accident, a Hyde Park man crashed his Ford SUV into a tree in the 6000 block of South Cornell Avenue -- less than two miles from his home -- at about 9:15 p.m. Wednesday, said Robert Perez, a police spokesman.

Vinston Glover, 57, of the 5400 block of South Ingleside Avenue, was taken to Northwestern Memorial Hospital, where he was pronounced dead at 10:31 p.m.

Hours later, a Chicago police SUV collided with a semi at about 1:40 a.m. in the 2600 block of West 79th Street in the Wrightwood neighborhood, said Officer Amina Greer, a police spokeswoman.

The officer was taken to Advocate Christ Medical Center in Oak Lawn for treatment of hand and arm injuries, Greer said.

A second officer was also in the SUV but didn't require medical treatment, police said. The semi's driver was also uninjured.

chicagobreaking@tribune.com