This year, the intersection of Olympic Boulevard and 26th Street is teeming with life. There’s been construction on the forthcoming Expo Line, which will bring art enthusiasts to Bergamot Station’s galleries nearby. Across the way, outdoor renovations have been underway at the Water Garden office complex, where workers will chat over coffee or lunch.

But for those who knew Leo Castillo, the intersection will always bring painful reminders. And on the anniversary of his passing in a tragic accident, family members and friends of the late 16-year-old are feeling his absence as much as ever.

A memorial mass has been scheduled for 7 p.m. Tuesday at Saint Anne Catholic Church, 2011 Colorado Ave., in Santa Monica.

The service will culminate a year of grief for the people who knew Castillo, a Santa Monica High School freshman remembered for his positivity and easygoing personality.

In the evening of May 10, 2015, Castillo was riding a motorized scooter northbound on 26th Street. A car driven by a 73-year-old Los Angeles man hit Castillo and a friend as they rode through the intersection at Olympic Boulevard against a red light, Santa Monica police have said. Castillo was pronounced dead shortly thereafter. His friend was taken to a trauma center in critical condition.

News of Castillo’s passing hit hard at Samohi, where students wrote messages to their late friend and classmate on a poster placed in the breezeway between the school’s administration building and cafeteria. The Grant Elementary School and John Adams Middle School communities also mourned their alumnus.

At his family’s home, a framed photo of a smiling Castillo was surrounded by flowers, candles and his favorite snacks: Sour Patch Kids candy and pinkish-red Brisk drinks.

A few nights later, at the JAMS choir concert at Samohi’s Barnum Hall, a tune was dedicated to Castillo’s memory.

It “was a beautiful song and just knowing that it was dedicated to Leo Castillo was a tear jerker,” one attendee wrote.

Meanwhile, scores of people rallied to support his family financially. A Samohi student set up a GoFundMe crowdfunding campaign to raise $15,000 for funeral costs and other expenses. The community raised more than $21,000. A funeral mass at Saint Anne’s last May 23 preceded a burial at Woodlawn Cemetery.

“We would like to thank each and every one of you for your generous donations and loving sentiments,” the family wrote at the time. “It is beautiful to see how much Leo is loved and remembered.”

Born Jan. 27, 1999, Castillo was also memorialized in a slideshow that was shown during a lunch at Samohi. He spent time with his family and at the beach. He posed with a costumed Homer Simpson character and wore cowboy hats. He rode a horse as well as the Goliath roller coaster at Six Flags Magic Mountain. He sported caps for Los Angeles sports teams as well as the Oakland Raiders.

“Leo brought so much joy,” Grant teacher Virginia Ripley said. “I remember him as pure sunshine.”