A school bus carrying grade-school students slammed through the front of a home in suburban Philadelphia on Tuesday, alarming residents and causing significant damage but injuring only the driver, officials said.

Nine students from St. Helena School were aboard the bus when it crashed in Blue Bell, Whitpain Township, at around 7:45 a.m., police said. They were evaluated by the school nurse and given soft pretzels by the principal.

The bright yellow bus remained on the front lawn, its front end wedged in the living room, for about five hours as police investigated.

"It's shocking, very shocking," said neighbor Joseph Smalley. "The kids, thank God, were OK."

The driver of the Wissahickon School District bus was injured and taken to a hospital; the extend of those injuries wasn't immediately clear, the fire chief said. Neighbors said he had no recollection of the crash and wanted to know if the children were OK. They said he may have blacked out. Four people inside the home were not hurt.

Neighbor Adam Glazer said he saw the bus accelerating up the windy street and wondered if it would stop. He said the bus swerved and knocked out a street sign before crashing into home.

Glazer said a student on the bus opened an emergency exit door and led her classmates out the back of the bus.

"Kids were very calm, surprisingly calm. They were talking amongst themselves," Glazer said. "Nobody was hurt, and everybody got lucky today."

The Catholic school, which serves students from prekindergarten through eighth grade in Blue Bell, posted a message on its Facebook page saying the students were doing well. The school thanked people for their prayers and concern.

"We are so grateful for their safety," the message said.