Linden Waddell of Silver Lake recalled the day 16 years ago when she saw someone placing a pink angel on her walkway.

"What's this?" Waddell asked.

"Angel delivery," the visitor said before scampering off.

Waddell didn't know it at the time, but she had just received one of 4,687 plaster cherubs -- 10 in every square mile of the city -- that were deposited free of charge in Los Angeles by artist Jill D'Agnenica and her merry band of friends.

The angel infestation began April 29, 1993, on the first anniversary of the L.A. riots, and D'Agnenica hoped that the 12-inch sitting figures would "symbolically link Los Angeles" and "appeal to the 7-year-old inside the guts of adults, even if for just a moment."

The project evolved into a sort of psychological experiment, testing how people felt about strangers bearing angels.