D.C. police reported two fatal shootings that occurred on the evening of July Fourth and in the early morning hours of Thursday.

The first happened just after 8 p.m. Wednesday as neighbors gathered in the Fort Totten neighborhood of Northwest; the second about six hours later at a cookout in Park View about two miles to the southwest.

No arrests had been announced as of Thursday evening. Police have turned to the community for help investigating the shootings: At a Wednesday news conference, D.C. Police Cmdr. George Kucik said authorities are still investigating what prompted the gunfire.

Authorities do not think the incidents are related. In the first, Kucik said, a large group was “hanging out” near First and Gallatin streets when three men approached on foot from the north, each carrying a handgun, and began shooting.

Several residents said they mistook the sound of gunshots for fireworks and only realized people had been shot when a crowd formed around one of the victims. Then, they said, people began to scatter. Residents interviewed for this story declined to give their names, citing concern for their safety.

Four people were shot, police said. Crevontai Key, 19, of Northeast was pronounced dead at a hospital. A man answering the telephone at a number listed for Key declined to be interviewed.

Two other people, who police said were juveniles, were taken to a hospital in serious condition. Updates on their conditions were not immediately available. A fourth person was taken to the hospital by a family member and later released.

In the second incident, police responded to a report of a shooting in the 600 block of Morton St. NW about 2:20 a.m. Thursday. Two suspects drove up on a group at a cookout and began shooting, according to police.

Two people were taken to hospitals with gunshot wounds, according to police. Julius Barnett Ellington, 35, of Northwest died of his injuries. The second victim was in stable condition, police said.

Police did not release detailed descriptions of the suspects in either incident.