The sirens were tested in unison at 10 a.m. on the last Friday of every month. In the 1950s and early '60s, neighborhoods were clustered in pockets across the Valley-each within earshot of sirens typically placed atop tall fire stations or attached to 30-foot steel poles.
When the siren was bolted to the top of a 15-foot tower on the roof of a city fire station near Coldwater Canyon Avenue and Ventura Boulevard in the early 1950s, residents were warned of the monthly tests so they wouldn't panic, she said.
Trees also partially screen a siren from nearby homes on Parthenia Street in Winnetka. In Encino, a 30-foot-tall siren is hidden among high-rise office buildings that have sprung up in recent years at Gloria Avenue and Ventura Boulevard.