LOS ANGELES (AP) — As Californians cut back water use and let lawns turn brown, arborists and state officials are worrying about a potentially dangerous ripple effect: Nearby trees going neglected and becoming diseased or dying.

With cities ordered to reduce water use by 25 percent during the state’s four-year drought, many residents are turning off sprinklers — not realizing that trees can be permanently damaged by the sudden water reduction.

Across California, 12 million trees died over the past year. While most of those deaths occurred outside urban areas, conservationists and officials are now focusing on cities.

Fears that parched trees could pose a danger were heightened this week when a 75-foot-tall pine fell on a group of kids, seriously injuring a boy and girl. The collapse hasn’t been determined to be drought-related.