Dan Schulte's parents were killed when Mark Mullan allegedly slammed into them while they were crossing the street in Seattle's Wedgwood neighborhood last month.
Both his wife and newborn son remain in the hospital with serious injuries.
"A tragedy like this it's really indescribable. It's something that's preventable. It's hit our family harder than most, but it can happen to anyone," Schulte said in a news conference at Seattle Children's Hospital Tuesday morning.
Schulte's recently retired parents, Dennis and Judith, were walking with their daughter-in-law, Karina, and their 10-day-old grandson, Elias, on March 25 when they were stuck in the crosswalk near Eckstein Middle School.
Schulte said he's hopeful his family's tragedy will eventually result in positive change. He's asking everyone to pledge not to drink and drive.
"We do think that the laws need to be tougher here in Washington and throughout the country. They're not stringent enough," Schulte said. He added that he knows lawmakers are working on DUI legislation in Olympia, but that there's a long way to go.
Schulte thanked everyone for all the support he and his family have received.
Schulte's sister, Marilyn, also spoke at the news conference and thanked her hometown in Indiana, where her parents were from.
"I also just want to say how amazing my brother is. He is literally the strongest person I know. He's an amazing father and husband."
Schulte said his son, Elias, has come a long way and is eating from a bottle now, but they don't know about his long-term recovery from brain injury. Schulte said the term 'miracle' has been used to describe his son's situation.
"We're really hopeful that he'll develop like a normal child."
As for his wife, Schulte said there are a lot of unknowns. She suffered a stroke, has trouble communicating and she has not yet had a chance to hold her son since the crash.
Prosecutors have charged Mullan, 50, with two counts of vehicular homicide, two counts of vehicular assault and one count of reckless driving in the crash. Mullan pleaded not guilty to all charges.
Police say his blood-alcohol level was .22, more than twice the legal limit, at the time of the crash.
If convicted, Mullan faces 15 to 19 years in prison. He remains in jail on $2.5 million bail.
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