Mary Witherspoon sued Mack in 1997, two years after her son Tonnie died while hauling a load of logs in rural Alabama. He lost control of his rig, which jackknifed and caught fire. Tonnie was trapped inside.
Witherspoon claimed her son would have lived had Mack installed an "inertia switch" similar to those used to activate air bags and seat belts during a crash. The switch could have stopped electrical arcs in the power system when the truck rolled over, preventing the fire, according to the suit.
Witherspoon's lawyer, Robert Cunningham Jr. of Mobile, AL, said Mack "never studied or researched this device. In fact, the electrical systems of trucks are still the same since the 1960s."
Newport Executive Editor Jim Winsor describes the device as a "pendulum" that reacts to vertical and horizontal motion. He says he's never seen one used in a heavy duty truck.
Other industry experts say truck makers do not use the switches because they are unreliable. The National Highway Traffic Safety Administration in 1975 asked truck makers for feedback about a proposal to require companies to install the switch, but the response prompted NHTSA to kill the proposal.
The Clarke County, AL, jury took less than an hour last week to return their verdict after hearing testimony from would-be rescuers about how Tonnie was burned alive.
Mack lawyers expressed sympathy for the family and said they are evaluating their options. An appeal is expected.