RIALTO, CA, January 7, 2026 -- At approximately 1:25 p.m., the Rialto Police Department responded to several calls reporting a traffic collision involving a motorcycle and another vehicle in the 1300 block of North Riverside Avenue. Patrol officers responded immediately and arrived at the scene within two minutes of the initial calls.

Upon arrival, officers found the motorcyclist, Juan Manuel Alvarez-Flores suffering from significant injuries and immediately began providing medical assistance. Rialto Fire Department paramedics arrived shortly thereafter, took over medical care, and transported Alvarez-Flores to a local trauma center. Despite these efforts, Alvarez-Flores later died from his injuries and was pronounced deceased at approximately 2:00 p.m. by hospital staff.

The driver of the second vehicle remained at the scene and fully cooperated with investigators. Based on preliminary information, alcohol or drug impairment does not appear to have played a role in the collision. The driver was not injured.

The Rialto Police Department’s Major Accident Investigation Team (MAIT) has assumed responsibility for the investigation and is continuing to examine the circumstances surrounding the collision. The investigation is ongoing.

Anyone with information related to this incident is encouraged to contact Traffic Sergeant Justin Breen at (909) 835-9965. Anonymous information may also be provided through WeTip at (800) 782-7463, referencing case number 932600279.