In a series of shootings that have taken place across Chicago over Memorial Day weekend, 40 people have been shot and four have been killed. 

The youngest of those killed was 15-year-old Veronica Lopez, who was shot to death on Lake Shore Drive the first night of the Memorial Day weekend. A black Nissan pulled up alongside Lopez and a 28-year-old man on the 2400 block of North Lakeshore Drive and opened fire. The man, who suffered a shot to the arm and a head wound, was stabilized, while Lopez was pronounced dead early Saturday morning, the Chicago Sun-Times reports

Later on Saturday a 23-year-old man was shot and killed in Portage Park on the Northwest Side, NBC Chicago reports. The man got into a fight with two other men at a gas station, where he was shot in the head and pronounced dead. 

The most recent fatal shooting took place Saturday night in Fuller Park on the Southside when a 27-year-old man was shot in the head, according to the Chicago Tribune. He was pronounced dead at the scene. 

The first homicide took place on Friday night in the Southwest Side when a gunman shot Mark Lindsay, 25, several times in the chest. Lindsey tried to drive away but crashed into another car and was later pronounced dead at Advocate Christ Medical Center in Oak Lawn. 

A series of nonfatal shootings beginning about five hours into Sunday morning have left 12 wounded, including a 17-year-old boy who was shot in the arm in the Roseland neighborhood, and a 26-year-old woman who was badly wounded in an East Garfield Park shooting. At least 23 other people have been wounded in this weekend's shootings, which began on Friday night.

As the Chicago Sun-Times notes, last Memorial Day weekend 12 people were killed and 43 were wounded in shootings across Chicago. The Chicago Police Department hasn't responded to our requests for comment about the shootings.