Incident: [XXX] Conditions: Clear daylight, dry pavement, normal highway conditions Crash/Injuries: Allstate Claim #[XXX]; several people injured At approximately [XXX], I was driving my 2020 Toyota Highlander Hybrid at about 55 mph in the slow/right lane. The vehicle ahead suddenly made a hard stop. I immediately and forcefully applied the brakes for an emergency stop. My front-seat passenger, [XXX], also saw the danger and yelled for me to stop at the same time. Based on our recollection, approximately five seconds elapsed between his warning and the collision. Despite the rapidly closing distance, the Toyota Pre-Collision System (PCS) did not appear to activate. There was no audible warning/beeping, no flashing red warning, and no “BRAKE!” indicator on the dashboard. This was also observed by [XXX] and [XXX], who was seated in the second row and is particularly attentive to warning signals. The vehicle also did not appear to provide any automatic emergency braking or brake-assist intervention. Despite my immediate and forceful braking, the vehicle did not stop in time and collided with the vehicle ahead, causing significant damage and injuries. The forward-facing sensors and windshield were clean and unobstructed. There were no dashboard warning lights or known system malfunction indicators before the crash. I purchased the Toyota Plus service package after completing the required maintenance during the initial coverage period. All scheduled maintenance and inspection