Aamer Madhani

USA TODAY

CHICAGO — With a holiday weekend spate of violence that killed 13 people, the homicide toll in the nation’s third-largest city hit 500, a grim milestone that puts the city on track to reach a murder rate it hasn't seen since the drug wars of the1990s.

The Labor Day weekend murders come after police recorded 92 murders in August, the deadliest month for Chicago since June 1993. With murders up roughly 50% for the year, Chicago has tallied more homicides than the much larger cities of New York and Los Angeles combined.

The city is on pace to record well over 600 murders for 2016, a threshold it has not reached since 2003. Chicago regularly recorded more than 700 murders a year in the 1990s as gang violence, driven by the crack-cocaine epidemic, raged.

In the most recent shooting on Monday night on the city’s West Side, someone in a silver mini-van opened fire on a group of teens and young men, killing two 22-year-old men and seriously wounding two teenagers, 16 and 17, and a 20-year-old, police said. One of the men killed was a gang member, police said. Police were searching for suspects Tuesday.

Chicago Police Superintendent Eddie Johnson has blamed the recent surge in killings on increased gang activity and weak gun laws.

"It’s important that we all wrap our heads around what’s going on here in Chicago," a frustrated Johnson told reporters Tuesday. "We need to enact tougher penalties, so these individuals know their actions will not go without consequences. Until then, you’re going to keep seeing the same results on the streets.”

The city recorded 473 homicides in 2015, according to police department data. Chicago surpassed the 500-murder threshold this year over the holiday weekend, according to data tracked by the Chicago Tribune.

While Chicago is one of several cities, including Milwaukee and Memphis, to see a spike in murder rates, other large cities have seen the number of killings decline in 2016.

New York, with 227 murders through Aug. 28, is on pace to record fewer killings than last year's total of 352. The nation's largest city tallied a record low 333 homicides in 2014. Outgoing Police Commissioner William Bratton said Tuesday that the department's officers are proving it's still possible to cut crime in the Big Apple.

"We have further reduced violence and serious crime across this city, yet again,” Bratton said. “The tremendous focus on a small group of criminals has resulted in these unprecedented declines in crime – as violence has increased in other American cities significantly."

Over the Labor Day weekend, Chicago experienced the most jarring spasm of violence in a span of 14 hours Monday, when nine people died.

On the city’s Southwest Side, a 24-year-old man and 47-year-old man were killed in a shooting near a city park around 7:13 p.m. Monday. The older victim told authorities before he died at a nearby hospital that he was walking a dog in the park when he heard gunfire from a vehicle. The second victim began running when he heard the gunfire and was struck as well, police department spokeswoman Officer Anna Pacheco said. It’s unclear what, if any relationship, the two victims had.

Chicago searches for answers to stem surging murder toll

A 33-year-old man was killed less than a half hour earlier, around 6:48 p.m., in a drive-by shooting in the Englewood neighborhood on the city’s South Side, one of the areas most plagued by gun violence. Someone in a light-colored vehicle opened fire at the man, striking him in the back, Pacheco said.

Three hours earlier, a 44-year-old man suffered fatal wounds to his head, neck and back while trying to escape from assailants. Police said witnesses noticed several people in a white van harassing the victim, who was in his own vehicle, before the shooting.

About 1:25 p.m., police were called to a home in the Brighton Park neighborhood, where they found a 22-year-old man lying dead in his driveway with a large chest wound. He also appeared to suffer several stab wounds to the chest, police said.

Chicago in the midst of most violent month since 1996

Additionally, police said a 24-year-old man was fatally shot in the Englewood neighborhood and a second man, 26, was critically wounded around 9:32 a.m. Authorities said both victims had known gang ties, and the 26-year-old man, who was wounded in the thigh and suffered a graze wound to the head, is refusing to cooperate with investigators.

Police were also called to a residence on the South Side early Monday morning where they found an 80-year-old man with a gunshot wound to the face. He was pronounced dead at the scene. Pacheco said the suspect, who has been arrested but not yet charged, shot the elderly man after an argument.

Follow USA TODAY Chicago correspondent Aamer Madhani on Twitter: @AamerISmad