Chaminade High School teacher and student on an academic tour of national historic sites were killed and nine others were injured Saturday when one of the vans in the school's caravan veered off an Arizona highway on the way to the Grand Canyon and overturned.

Chaminade High School junior Brendan Tracey and Brother Lawrence John Zarzycki, a Chaminade math teacher at the all- boys Mineola school, were pronounced dead at the scene in Valle, Ariz., Saturday morning.

The crash occurred at 11:45 a.m. as the van, a 2000 Dodge, was traveling north on Route 64, the main road leading into the Grand Canyon. Authorities said the van veered off the road, but they don't know why.

As Zarzycki tried to regain control of the van, he overcorrected, which caused the van to overturn, according to Pam Andrews of the Arizona Department of Public Safety.

Two of the teenagers, Kevin Pedersen, 16, and James Iovino, 16, were hospitalized at Flagstaff Medical Center in Flagstaff for observation, but hospital personnel would not release information about the boys' condition yesterday.

Brother Joseph Bellizzi, the school principal, and other school officials left for Arizona yesterday. They expect to return this afternoon.

"Chaminade is a family of faith, and our mood is of prayer and reflection," said Brother James Williams, school president. "This was a spiritual trip and we are responding to this with faith." The USA Study tour is a popular three-week summer trip that hundreds of students vie for every other summer. Between 20 and 25 students are selected to participate in the program, which features a different itinerary each trip.

"It was both educational and spiritual trip of sites in the Midwest and Southwest," said Williams of the 30-year-old program. "It's very popular." Though the group was in several vehicles, only one was involved in the accident. Zarzycki and Brendan were taken from the scene to the Flagstaff hospital. Six other boys were treated at the hospital and released. They are: Matthew Karl, 16; Matthew Loporto, 15; Malachy Soller, 15; Edward Katime, 17; Jonathan Keeling, 17; Andrew Trentacoste, 17. Brother Benjamin Knapp, 25, was also treated and released.

The students left LaGuardia Airport a week ago and flew into Salt Lake City, Utah. They traveled by van to various sites, before heading for the Grand Canyon.

Zarzycki, 38, a 1980 graduate of Chaminade, lived in the school's faculty residence since becoming a teacher in 1985. He taught math and a course designed to teach other students "how to teach religion," Williams said. He was also the head of Chaminade's math club, which competed against various schools.

Brendan, 16, recently completed his sophomore year and was an editor of the school's yearbook, the Crimson and Gold. He was active in the Emmaus Society, a school-run volunteer organization, Williams said.

"Not too long ago he planted a garden at a nursing home in Queens," he said. "He was a very generous and outgoing young man." Yesterday, anyone calling up the Catholic school's homepage immediately saw news of the fatal crash, along with a message to "please keep Brendan, Bro.

Lawrence, and their families in your prayers." The school's general voicemail also promised regular updates.

Brendan's relatives in Garden City declined to comment and asked for privacy in order to mourn.

School friends were also in mourning.

"I'm so distraught right now I can't think straight," said Garret Zarembo, 16, who has known Brendan since grade school. "He was always there showing me the ropes." He said Brendan was liked and respected by his peers who admired his pious and affable demeanor. "If I really wasn't sure about something I felt most comfortable asking him because I knew he wouldn't be judgmental," he said. "He was always smiling even if I said something that was totally not funny." Funeral arrangements had not been made as of yesterday afternoon.

Staff writer Tom Demoretcky and Frank Dell'Aglio contributed to this story .   Story was posted in Newsday.