(CNN) -- A train passenger found dead last week beside the tracks died from multiple injuries including a broken neck, the Georgia Bureau of Investigation said Monday.
Barbara Arteta, 63, of New Smyrna Beach, Florida, was found Thursday between mile markers 553 and 554 on CSX tracks in south Georgia. Arteta was reported missing by her husband, Gene, Thursday morning when the train arrived in Sanford, Florida, after travelling from Lorton, Virginia, overnight.
Special Agent Mike McDaniel of the Georgia Bureau of Investigation termed Arteta's death "suspicious." He would not provide details on any interviews or leads.
GBI agents are looking for passengers who were aboard Amtrak Auto Train No. 53, particularly passengers who were in cars 5310, 5311, 5312 and 5313 and in the lounge area, the bureau said.
Investigators were looking into whether an emergency window in the car in which Arteta was traveling was open, McDaniel said. Arteta's husband, Gene, told CNN affiliate WFTV that his wife was incapable of climbing up to a window.
The Artetas were returning to Florida after seeing a newborn grandchild, according to WFTV. They were aboard the popular Amtrak Auto Train, which carries vehicles and passengers, and planned to drive home once they arrived in Sanford, Florida.
Gene Arteta told WFTV that his wife suffered from Parkinson's disease and began to shake early Thursday, so he moved to another seat to get some sleep. When he woke up, he said, she was gone.
"Why is she dead on an Amtrak train? It was her first time on an Amtrak train. She was so happy and proud. I don't get it," Arteta said.
"I don't even see how that could even happen," he said.
The train passed through the Jesup, Georgia, area between 3 a.m. and 3:30 a.m. Thursday, said McDaniel, who heads the GBI office in Kingsland.
Gene Arteta said he awoke around 5:45 a.m. to find his wife missing, McDaniel told CNN. He began searching for her and asked for help. The Sanford Police Department was officially notified of a missing person around 9 a.m., McDaniel told CNN.
Barbara Arteta's body was spotted by the crew of a CSX train near Jesup around 3:20 p.m. Thursday, the agent said.
Gene Arteta told WFTV that about $1,000 was missing from his wife's purse. McDaniel confirmed the purse was found, but would not comment on its location or contents.
The investigation involves several states and jurisdictions, McDaniel said. GBI investigators spoke with the Arteta family in Jesup on Friday. "They are cooperating with us," the agent said.
Asked if it's possible Barbara Arteta fell, McDaniel said "anything was possible."
The GBI asks passengers or anyone else with information to call its tips line at 1-800-597-8477.
CNN's Phil Gast contributed to this report.