PHOENIX -- Three people were taken to hospitals after a collision involving a school bus and two other vehicles in Avondale, on the west side of metropolitan Phoenix.

The bus from the Litchfield Elementary school district had 40 children on board, fire units reported. All but one of the children were uninjured, and were transferred to another bus where they continued the trip to Wigwam Creek Middle School.

An 11-year-old girl, a woman in her 30s and an infant were transported to the hospital, a fire department spokesman said.

According to fire crews at the scene, a truck was heading eastbound on Indian School Road and ran the red light at Santa Fe Trail. The truck hit the school bus, which was making a left turn onto Santa Fe Trail, which then collided with another van.

The first unit at the scene called the collision a one-alarm medical emergency, according to scanner reports.

Crisis dog Topaz was sent to the scene. When the students arrived at Wigwam Creek Middle School in Litchfield Park, they were greeted by the Glendale Fire Crisis Response Team and Topaz. "Somehow the focus was taken off of the incident itself and put on to this dog," said Cathy Butt, the school's assistant principle.