Volunteer firefighter Stephen Whitcomb in Brookline, New Hampshire, tended to a Christmas Eve car wreck without knowing that the female victim of the accident was his 30-year-old daughter. Officials are investigating the three-car accident that killed Katie Hamilton and whether criminal charges are warranted. Hamilton was on her way to work Tuesday morning after dropping off the girls at their grandmother's house. Just before 9:05 a.m., Hamilton was preparing to turn left when another car struck her 2006 Ford Explorer from behind, Brookline police said. The force from the other vehicle, a 2009 Toyota Tundra pickup, caused Hamilton to veer into the northbound lane, where a 2004 Ford F250 pickup struck her broadside, police said. Police identified the Tundra's driver as 31-year-old Greg Cullen. Brookline Police Chief William Quigley told NBC News that neither alcohol nor speed appeared to be factors in the crash, although "driver inattentiveness" could be a likely cause.