A Naples man who suffered serious head and leg injuries in a crash that killed a mother and daughter in Casco last week remained hospitalized Thursday, but his condition had improved slightly.

Austin Wood’s condition Thursday was listed as serious, said Caroline Cornish, a spokeswoman for Maine Medical Center.

Wood, 26, was listed in critical condition on June 5 after his SUV was struck head-on by another SUV on Route 302 in Casco.

The driver of that vehicle, 53-year-old Jamie Mantz, and her mother, 80-year-old Carol Strom, were both killed. The Cumberland County Sheriff’s Office, which investigated the crash, said that Mantz crossed the center line for unknown reasons.

Emergency crews had to extricate all of the drivers and passengers and Route 302 was closed to traffic for more than five hours.