A Woodbridge family is shattered after a fatal bus accident on Thursday left their daughter and sister dead.

"No words can express how much pain we feel right now," a sobbing Simon Tran told CTV Toronto on Friday about the death of his daughter Catherine.

Simon, his wife and younger daughter showed up at the scene where the 16-year-old died.

Classmates of Tran's at Woodbridge College said Friday she was a wonderful girl who liked to make people laugh and made friends easily. They described her as a hardworking, excellent student.

Her parents say Catherine excelled at math and science. She hoped for a career in medicine.

One girl said, "It's weird, because you think you can't die when you're this young."

Debra Conrad-Knight, the school's principal, said: "Catherine was a wonderful student, and we deeply feel her loss at our school."

At about 3:45 p.m. a York Region Transit bus was travelling westbound on Chancellor Drive, approaching its intersection with Pine Valley Drive. It started to make a left turn to go south on Pine Valley Drive, York police said in a news release issued Friday.

"At this time, a 16-year-old female pedestrian from Woodbridge was crossing in the intersection of Chancellor Drive Avenue and Pine Valley Drive. As the bus entered the southbound lanes, it struck the pedestrian in the crosswalk. The female succumbed to her injuries at the scene."

Catherine didn't die immediately as she lay trapped under the bus. "We're talking to her. She was pinned underneath the bus, and we were trying to tell us to stay with us," said Jackie, who witnessed the horrible event.

"She was talking to us, and she was asking for help, but we really couldn't help her much. She was pinned."

Emergency workers frantically worked to save her, but they couldn't do so.

"There is nothing you can do but stand there and pray, and pray for that young girl," added Sarah, another witness.

Police continue to investigate the accident. The bus driver is said to be in shock. The Trans want to know why he didn't see their daughter.

A small memorial of flowers, cards and teddy bears is growing near the scene where Tran died, which is less than a block from her home.

Thursday was a deadly and dangerous day for GTA pedestrians.

At 6 p.m., a car struck a 49-year-old woman who had exited a bus and was trying to cross Birchmount Road mid-block just south of Rolark Drive.

She was pronounced dead at the scene.

About an hour later, paramedics took a 52-year-old woman with serious head injuries to the trauma centre at Sunnybrook hospital. A car had struck her.

That incident happened at Jane Street and Falstaff Avenue, which is just south of Highway 401.

Brampton fatality

Peel Police issued a news release Friday appealing for witnesses to a fatal accident that claimed the life of an elderly pedestrian in Brampton on Friday.

"The victim was walking near Queen Street East and Scott Street. At approximately 2:30 pm, the victim attempted to cross Queen Street, when he was struck by a vehicle," they said in a news release.

Paramedics took the man to hospital, but he died about an hour later.

"The investigation is being conducted by members of the Major Collision Bureau. Anyone with information pertaining to this incident is asked to call (905) 453-2121, ext. 3710," police said.

People can also call Peel Crime Stoppers at 1-800-222-TIPS (8477), by visiting www.peelcrimestoppers.ca, or by texting "PEEL", followed by their tip, to CRIMES (274637).

With a report from CTV Toronto's John Musselman