INGLEWOOD, Calif.  They came for new teeth mostly, but also for blood pressure checks, mammograms, immunizations and acupuncture for pain. Neighboring South Los Angeles is a place where health care is scarce, and so when it was offered nearby, word got around.

For the second day in a row, thousands of people lined up on Wednesday  starting after midnight and snaking into the early hours  for free dental, medical and vision services, courtesy of a nonprofit group that more typically provides mobile health care for the rural poor.

Like a giant MASH unit, the floor of the Forum, the arena where Madonna once played four sold-out shows, housed aisle upon aisle of dental chairs, where drilling, cleaning and extracting took place in the open. A few cushions were duct-taped to a folding table in a coat closet, an examining room where Dr. Eugene Taw, a volunteer, saw patients.

When Remote Area Medical, the Tennessee-based organization running the event, decided to try its hand at large urban medical services, its principals thought Los Angeles would be a good place to start. But they were far from prepared for the outpouring of need. Set up for eight days of care, the group was already overwhelmed on the first day after allowing 1,500 people through the door, nearly 500 of whom had still not been served by day’s end and had to return in the wee hours Wednesday morning.