Two people drowned in separate incidents along the Russian River Sunday, prompting renewed safety warnings amid a troubling pattern of summertime deaths on the popular Sonoma County waterway.

The first drowning victim, a juvenile, was found underwater after a 20-minute search at Monte Rio Beach during an afternoon rescue attempt that included a second juvenile, the Sonoma County Sheriff's Office said. One of the juveniles was rescued, but the second was declared dead at the scene after attempts at CPR.

Two people died in unrelated drowning incidents on the Russian River on Sunday, the Sonoma County Sheriff's Office said.