(CBS) — City clean-up crews, aided by ex-offenders from the Safer Foundation, were busy in the West Humboldt Park neighborhood Saturday.

More than three dozen people took part in the one-day blitz, the fifth of 12 scheduled this summer.

A trimmer reduced a dead ash tree in front of 4250 West Augusta Boulevard to twigs and mulch in 15 minutes, as city workers and volunteers began to clear a vacant lot of debris with rakes, shovels, weed-whackers and mowers.

City transportation crews were re-lining the intersection of Augusta Boulevard and Kildare Avenue, and others spread out, working mostly north and west, with Ald. Emma Mitts (37) and First Deputy Transportation Commissioner Randy Conner overseeing the work.

“We want every alley and every street to be safe, well-lit, smooth and well-marked,” Conner said.

Mitts said the clean-up helps to grow community pride and drive away crime.

Conner said that the four previous blitzes cleaned away 7,980 bags of trash and 3,103 dead trees, spruced up 609 vacant lots and 274 viaducts and used up 455 cubic yards of mulch.