Witnesses testified Wednesday that a bicyclist charged with felony vehicular manslaughter for striking a pedestrian in San Francisco's Castro District last year was speeding and ran a red light before the fatal collision.

The testimony came at the start of the preliminary hearing for Chris Bucchere, 36, who struck 71-year-old Sutchi Hui at Castro and Market streets at about 8 a.m. on March 29, 2012. Hui died at a hospital days later.

The first witness to testify was Wen-Chih Yu, a woman who was just a few feet away from Hui when the collision happened.

"He was going incredibly fast," Yu said of Bucchere.

She said Bucchere yelled before he hit Hui but did not appear to slow down.

Yu was shown a video of the collision that showed Bucchere riding south on Castro Street through the intersection before striking Hui, who was in the crosswalk headed east on Market Street.

Angelo Cilia, another pedestrian in the crosswalk, testified that he "heard a sound that was rather bone-crunching" and that he also didn't see the bicyclist slow down prior to the collision.

A third witness, Nathan Pollak, was driving south on Castro Street alongside Bucchere and said he saw Bucchere run multiple red lights and stop signs in the minutes before the accident.

Pollak said that instead of slowing down, Bucchere "crouched down" to accelerate through the intersection at Castro and Market.

"My jaw dropped," Pollak said.

The preliminary hearing, which will allow a judge to determine whether there is enough evidence for Bucchere to stand trial, was continuing late Wednesday morning.

The case gained further attention after the collision when it was revealed that on the day of the collision, Bucchere wrote about the accident on an online cycling forum.

In the post, he wrote that he hoped Hui was OK, but ended by saying the moral of the story was the importance of wearing a bike helmet. The post drew criticism from other forum members and was later taken off the site.