It remains unclear why a young man and woman were on railroad tracks near a farm in Sale Creek when they were struck by a locomotive Monday morning.
The deaths of 27-year-old Michael Hennen and 19-year-old Hannah Barnes bring the number of pedestrians killed by trains up to three this year in Hamilton County.
Jill Moody, state coordinator for Operation Lifesaver, a nonprofit dedicated to train safety, said people should treat railroad tracks as though a train is coming even if one is not in sight.
"We want people to always expect a train," she said.
Nearly half of collisions, whether they're with people or vehicles, take place within five miles of someone's home, Moody said, citing records from the National Highway Traffic Safety Administration.
Norfolk Southern, which owns the rail line where Hennen and Barnes were killed, said trains pass on those tracks as many as 25 times per day with no precise schedule.
Railway officials said the train crew saw something on the tracks and blew the horn. They contacted authorities after the accident.
Pamela Rymer O'Dwyer, a local attorney who specializes in railroad litigation, questions whether the train blew its horn since the crossing is on private property.
"If these people were caught unaware, it would be my belief there was some flaw in the horn itself or the horn was not blown," she said.
Even if the horn were blown, she said people underestimate the speed of the train, don't know the direction of the sound and often panic by going in the wrong direction, she said.
The train also was equipped with a rail view camera. Investigators with Hamilton County Sheriff's Office plan to view the images to learn more about what happened leading up to the accident.
Hennen was the son of Tim and Corinne McDonald Hennen, who own Hennen's Restaurant in downtown Chattanooga and established Big River Grille. Michael Hennen was also the great-grandson of Roy McDonald, who founded the Chattanooga Free Press and was the longtime publisher of the paper.
Michael Hennen was the grandson of Frank McDonald, who was the chairman and president of the paper from 1969 to 2000.
Outside the McDonald residence on Coulterville Road, where Barnes and Hennen were killed, the mailbox still reads "Roy McDonald."
A manager at Hennen's Restaurant declined to comment on behalf of the family Tuesday afternoon.
Barnes was a granddaughter of Dr. Marion Barnes, who was president of Covenant College from 1965 to 1978.
In Hamilton County, there are a total of 276 railroad crossings with 80 of those crossings on private property, according to data from the Federal Railroad Administration.
Statistics show there were three pedestrians killed by trains in Hamilton County in 2008, but none in 2009 and 2010.
Steven Underwood, 40, was killed attempting to save his dog from the railroad tracks in Soddy-Daisy near Bean Street and Daisy Dallas Road on April 26.
Statewide, there have been four pedestrian fatalities from January through May this year, according to Federal Railroad Administration data. For the same time period in Georgia, there were five.
After a train accident, data takes about six months before it's included in Federal Railroad Administration records.