Gina Rower brought her children and friends to place flowers and ribbons on a makeshift memorial near the site of a CSX train derailment.
Killed in the derailment were Elizabeth Conway Nass and Rose Mayr, both 19, of Ellicott City.
Rower said that she didn't know the girls, though her son, Justin, said that one of the girls did babysit for a family acquaintance.
"We're just here to mourn the loss," he said. "I just feel bad that they died," he said. "It's a horrible loss."
Tuesday night, hundreds of people gathered in the parking lot of the girls' alma mater, , for an impromptu vigil.