Date: Oct. 13, 2009

Victim: Stephen Lagakos, Regina Lagakos, Helen Lagakos, Stephen Krause

Location: Peterborough, N.H.

Model: 2005 Toyota Highlander

Details: Stephen Lagakos, his wife, Regina Lagakos, and his mother, 94-year-old Helen Lagakos, were returning from a birthday celebration at the family's lakeside country house in Rindge, N.H., when other motorists observed Lagakos' 2005 Highlander traveling at high speed, passing other vehicles erratically in the breakdown lane, according to a complaint filed with the National Highway Traffic Safety Administration.

All three were killed when the Toyota collided with a Chevrolet Malibu on U.S. 202 near Peterborough. The driver of the Malibu, 56-year-old Stephen Krause of Keene, N.H., also died.

Reported by friends and family to be an exceptionally experienced and safe driver, Stephen Lagakos, 63, was a professor at Harvard University's School of Public Health. Colleagues said his work in statistical science was critical to unraveling environmental mysteries, including the contaminated water wells of Woburn, Mass., a toxic site that was the subject of the 1996 bestseller "A Civil Action " by Jonathan Harr,which was later made into a movie starring John Travolta.

The NHTSA complaint filed in January by Marvin Zelen, Lagakos' boss, suggested that the accident was caused by sudden unintended acceleration. Zelen wrote that Lagakos was a careful driver with an excellent safety record.

"I had been in his car with him hundreds of times. Very safe driver -- no cowboy," the report said. "Believe car had uncontrolled acceleration."

-- Stuart Pfeifer, Carol J. Williams and Robert Faturechi