A New Jersey teenager who tweeted Sunday night that someone was in her house and implored her followers to call 911 likely left her home voluntarily.
Kara Alongi's disappearance is now being investigated as that of a runaway juvenile.
Her parents returned home around 7:20 p.m. and called police, about an hour after the Arthur L. Johnson High School girl tweeted, "There is someone in my hour call 911."
Family members were away at the time of the tweet, and returned home to find Alongi missing.
They called police to report a burglary and a missing person, but when police arrived at the house they found no signs of forced entry or stolen property, Clark (N.J.) police chief Alan Scherb said.
A door was unlocked.
Police K-9 units tracked her scent from the back door of the house, through a neighbor's yard and around the corner back onto her block where the scent went cold.
Detectives then found that someone called a local taxi company asking for a car at Alongi's address around the same time as the tweet, and found a solid lead.
A driver said he dropped off a person matching the girl's description at an area train station; it is not clear whether she got on a train. She left her cell phone at home.
Scherb said police have not determined whether Alongi will face any kind of penalty or punishment, as all efforts are focused on locating her and bringing her home.
"We don't know why she sent (the tweet) out," Scherb said.
"Right now we are not looking at any charges."
Alongi's tweet went viral, with thousands of messages about Alongi's reported disappearance and efforts like the hashtag #helpfindkara trending nationally on Twitter.
As of Monday, Alongi had more than 94,000 Twitter followers. Clark police were flooded with an estimated 6,000 phone calls after Alongi's tweet spread like wildfire.
"It sent more manpower (down) these wrong-way streets," Scherb said. "It hampers us because we have to follow up on what are ultimately bogus leads."