Gang-related crimes plunged 40 percent on average - and more than 80 percent in some areas - around parks and recreation centers that were part of this year's Summer Night Lights program, it was announced Tuesday.

"Today's Summer Night Lights has become a crowning achievement in our gang reduction efforts and a source of pride in some of our most crime-ridden communities," said Mayor Antonio Villaraigosa, whose Office of Gang Reduction and Youth Development runs the program.

"This year, we took 24 of the worst gang-plagued communities in the city and transformed them back into community centers for hundreds of thousands of families and children to enjoy without the fear of violence," he said.

From Independence Day until Labor Day, Summer Night Lights kept two dozen parks open until midnight on Wednesday through Saturday nights, providing the community with family programs, after-school activities, arts initiatives and athletic leagues. The LAPD reported that gang-related homicides dropped 57 percent; aggravated assaults, 48 percent; and shots-fired calls, 55 percent.