The nation's largest homeless census is being conducted this week with thousands of volunteers sweeping 4,000 square miles of Los Angeles County to tally the number of people who lack permanent housing.
The Los Angeles Homeless Services Authority said Tuesday the census will be conducted over three nights by trained volunteers.
The authority conducts the survey every two years to better allocate resources to the homeless. After the initial count, a deeper survey will be conducted to find out gender, ethnicity and medical condition of homeless people.
The 2009 census found 42,694 people living in places unfit for human habitation, including cars, sidewalks, parks, abandoned buildings and shelters. Los Angeles County has the nation's largest homeless population.
Copyright 2011 The Associated Press.