CHICAGO_The reverse thrusters that should have slowed a Southwest Airlines jetliner before it slid off a runway and into a busy street didn't immediately kick in when the pilots tried to deploy them, federal investigators said Saturday after interviewing the crew.

The flight attendants said they could tell the Boeing 737 wasn't slowing after it touched down in the snow Thursday evening, and the pilots said they applied the brakes manually as soon as they realized something was wrong, said Robert Benzon, National Transportation Safety Board investigator in charge.

"They all said it was a smooth landing but they could sense a lack of deceleration," Benzon said.

The plane, with 98 passengers aboard, slid off a 6,500-foot runway at Midway Airport, through a fence and into street traffic, where it hit two cars and killed a 6-year-old boy riding with his family. Ten people, most of them on the ground, were injured.

Funeral arrangements are being made for Joshua Woods, and an attorney for Woods says a trust fund for the boy's family also is being created. Woods, his two brothers, mother and father were passengers in one of the cars.

Attorney Ronald A. Stearney says Woods' father, Anthony, was released from the hospital yesterday. He suffered several fractures to his face and back of his head. The boy's brothers suffered only cuts and bruises. Their mother left the hospital last week.

Investigators are still trying to determine how much of a role the braking equipment played in the accident.