A 20-year-old woman who grew up on the Island and dreamed of being a teacher was killed Tuesday evening when the vehicle she was driving was struck by a delivery truck at the intersection of County and Edgartown-Vineyard Haven Roads.

Brandy Marie Gibson, who graduated from the Martha’s Vineyard Regional High School in 2004 and recently worked as a substitute teacher in Vineyard Haven and Edgartown, was pronounced dead at the Martha’s Vineyard Hospital around 11 p.m. Tuesday night.

According to police, Ms. Gibson was driving east on the Edgartown-Vineyard Road in a 1993 Oldsmobile around 10:30 p.m. when she collided with a delivery truck turning left from County Road.

The two occupants of the truck — driver Francellyo Dias and passenger Keila Lessa — were brought by helicopter to Brigham and Women’s Hospital in Boston. As of yesterday morning, Mr. Dias, 25, of Vineyard Haven, was listed in critical condition, although a hospital spokesman said she could not comment on Ms. Lessa’s condition.

Mr. Dias, 25, was driving a delivery truck owned by Humphreys Sandwiches, a deli with stores in Vineyard Haven, Oak Bluffs and Edgartown. Police said Mr. Dias was unable to present a valid driver’s license at the scene, and may be charged with operating a vehicle without a license.

Oak Bluffs Sgt. Michael Marchand said Humphreys may also be cited for allowing an unlicensed operator to drive a company vehicle.

Joseph (Michael) Diaz, the owner of Humphreys, did not return telephone calls from the Gazette.

Sergeant Marchand said additional charges may be filed depending on the findings of a crash reconstruction conducted by the Oak Bluffs and state police on Wednesday. The accident remains under investigation by Oak Bluffs officer James Morse and state police trooper David Parent.

Police said Mr. Dias was turning left from County Road onto Vineyard Haven-Edgartown Road when the front wheel of the delivery van struck the vehicle driven by Ms. Gibson. “[The van] struck with enough force to push both vehicles back some 50-plus feet,” a press release from police said.

Police have yet to determine how fast either vehicle was traveling at the time of impact, although it has been determined that no one involved in the accident was wearing a seat belt.

According to court records, Mr. Dias, a native of Brazil, was charged in June of 2006 with operating a motor vehicle without a license and operating a vehicle without insurance. He paid $252 in fines and received one year probation. He was then charged in March of 2007 with operating without a driver’s license and a marked lane violation and paid $200 in fines and performed eight hours of community service.

Ms. Gibson came to the Vineyard at a young age to live with her grandmother Carol Berryman. After her grandmother died in 2006, she moved in with Mary Vivian, a school nurse.

Friends of Ms. Gibson this week described her as a fighter and a young woman who overcame a great deal of adversity in her life. She recently seemed to find her calling as a substitute elementary teacher, friends said. She aspired to become a full-time teacher, was working toward her associate degree and dreamed of opening her own day care center.

“Whatever happened in her life she just bounced back and fought through it,” said Maureen Deloach, principal of the Tisbury School.

Mrs. Deloach said the Tisbury School awarded Ms. Gibson the principal’s award in the eighth grade, one of the school’s top honors, for her hard work and dedication.

She said Ms. Gibson felt comfortable at school and was eager to help out whenever possible. She would volunteer to raise the flag in the morning and read the announcements in the afternoon, and even came into school during the summer to help mail information to parents and students.

“I think the school became a second home to her, and we were happy to have her. She was such a beautiful girl inside and out,” Mrs. Deloach said.

Margaret (Peg) Regan, principal of Martha’s Vineyard Regional High School, remembered Ms. Gibson as someone who didn’t let life get her down.

“She didn’t get a lot of breaks in life. But that never slowed her down . . . she learned to do things on her own and she stayed positive and she made friends easily,” Mrs. Regan said, adding:

“It’s so sad when a young person like Brandy is not able to live out her potential, and she had so much potential. She would have made a great teacher.”