The vigil was held at El Monte High School at 7 p.m. Castro was remembered as a popular football and baseball player who fellow students referred to as a positive role model. He transfered to El Monte as a sophomore and had many friends on and off the field.
During the vigil, Castro's parents met a survivor who was sitting right behind the 19-year-old when the accident occurred.
Bus crash survivor Abram Garcia met Castro on the trip to Humboldt State and said even then he made a huge impact in his life.
"He was sitting right next to me, and I didn't really know anyone, and I was kind of shy going in, and he just talked to me in open arms," said Garcia in tears.
His family says they're overwhelmed and grateful for the amazing show of support. His friends said they will always remember his big smile, generous laugh and outgoing personality.
"I felt the worst pain ever, but it makes everything feel better when you have so much support here," said Castro's brother, Roman. "I loved him and I'm pretty sure a lot of people here did too."
Castro wanted to be the first in his family to attend college.
"He was a motivator, he was a dreamer, and I won't let his dreams go to waste," said Castro's teacher Trevor Schoenfled. "Today, I urge my students to take his passion for learning as an example of how to carry on."
Castro was among the first identified from a Thursday crash that killed 10 people on the Interstate 5 near Orland, including five students and three adult chaperones.
A FedEx truck sideswiped a Nissan Altima before colliding with a bus carrying 44 Southern California students headed to Humboldt State University for a college tour. Dozens of injured students escaped through windows before the vehicles exploded into towering flames and billowing smoke.
The victims have been identified as Arthur Arzola, 26, a Humboldt State University recruiter from Rancho Cucamonga; chaperones Michael Myvett and Mattison Haywood, who were engaged; Adrian Castro, an El Monte High School student; Marisa Serrato, a student at Norte Vista High School in Riverside; Ismael Jimenez and Denise Gomez, students of Animo Inglewood Charter High School; Jennifer Bonilla, a student at Dorsey High School in Los Angeles; bus driver Talalelei Lealao-Taiao, and FedEx driver Tim Evans.
FedEx driver identified as father of two
Evans was the last victim identified Monday. He had married his highschool sweatheart and was a father of two daughters. He helped coach their soccer and softball teams.
Drivers in NorCal crash had clean records
California's Department of Motor Vehicles said neither driver had a moving violation, although The Sacramento Bee reported that Lealao-Taiao's license was briefly suspended in 2004. The reason for the suspension was not immediately clear.
Twin among 10 dead in NorCal crash
Riverside resident Marisa Serrato, 17, was on the stricken bus and died in the crash. She was a well-liked, church-going attendee of Norte Vista High School.
On Monday, Marisol spoke to Eyewitness News on dealing with the heartbreak of losing her identical twin sister Marisa. The two shared a room and their walls were decorated with their academic achievement awards and art.
"She was a gift to me. She was the most precious gift God gave me, and now I have to move on - he took her back," said Marisol.
She says the two of them were inseparable, but because Marisa had been put on a wait list for the trip, she ended up on a different bus. Upon arrival, Marisol was told her sister's bus had been involved in an accident, and that some people had died.
"I was panicking, I was really panicking, because I knew my sister was on that bus. 'My sister is on that bus', I remember saying that, and I began praying in my seat and hoping she was OK, but God put her to rest. I'm pretty sure there's a good reason why God put her to rest and she's not suffering no more with us," said Marisol.
Marisol says she doesn't understand why her life was spared, instead of her sisters.
"Why her, and why not me?" said Marisol. "Why me? Why did I get to live and why did she get to die? I ask my self many times, but I don't know if I may ever find the answer to that."
Student saves others, dies in NorCal bus crash
Ismael Jimenez, 18, an Animo Inglewood Charter High School student, is being hailed a hero. After the fiery collision, Jimenez broke open a window at the front of the bus as it filled with smoke and lifted students to safety. He later died.
A baseball-inspired vigil was held in memory of Jimenez Saturday and Denise Gomez, another student killed in the crash. Gomez, 18, was a described as a bright student who was part of the soccer team, president of Earth Club and an editor of the school yearbook. Both would have been the first in their families to attend college and were considered model students.
Memorial set for Rancho Cucamonga victim
Arthur Arzola, a recruiter for Humboldt State University, was the first of the 10 fatalities to be identified. Arzola, a 26-year-old from Rancho Cucamonga, was just one month away from completing his master's degree in educational counseling at the University of LaVerne.
A campus memorial is planned for 7 p.m. on Wednesday at Morgan Auditorium. Funeral services for Arzola will be held at 10 a.m. on Friday, April 18 at SkyRose Chapel at Rose Hills Memorial Park.
A preliminary NTSB report is expected within 30 days; the entire investigation can last more than a year.
On Monday, the California Highway Patrol asked witnesses who took photographs of the video of the collision to contact Officer Lacey Heitman by phone at (562) 225-2715.
CNS and The Associated Press contributed to this report.