Tweets indicate Elizabeth Nass and Rose Mayr, both 19, were sitting on the edge of the Ellicott City bridge when a train traveling atop the bridge derailed, burying the best friends in coal, The Baltimore Sun reported Wednesday.
When police recovered their bodies, they were still seated on the edge of the bridge, the newspaper said.
Howard County police said it appears Mayr posted a snapshot of their feet and the message "Levitating" moments before the derailment occurred.
Earlier Nass wrote on Twitter "Drinking on top of the Ellicott City sign."
Some 250 people attended a candlelight vigil for the girls Tuesday night.
The two had known each other since elementary school and had recently resumed their close friendship, said Mark Mayr, Rose's father.
Monday night was their last get-together before leaving for junior year at college.