Ventilation has become a life or death issue as as experts find that COVID-19 infections increase in poorly ventilated interiors. DnA looks into the extreme measures being taken to improve air conditioning and asks whether outside air is cheaper and healthier. D.J. Waldie has a writerly gift for divining the “sacred ordinariness” in the fabric of Los Angeles. In his new book “Becoming Los Angeles: Myth, Memory, and a Sense of Place,” Waldie reckons with himself and the region in a post-George Floyd world, while illuminating details of LA life, from telecopters to the tiles at Union Station.