To the thousands of motorists driving along Route 1 in Philadelphia, the Roosevelt Inn looks like any other roadside city motel.

But there, inside a guest room, a 14-year-old girl was "sold into sexual slavery," barred from leaving for months and forced to engage in sex acts with 1,000 men as motel staff looked the other way, according to a new lawsuit.

The suit -- the first of its kind in Pennsylvania -- targets the motel and its owners in seeking civil compensation for the victim, now 17. It also serves as a nationwide warning to hotels and motels knowingly profiting from child sex trafficking, according to lawyers for the girl.

"This lawsuit sends a clear message that you need to police your hallways and you cannot profit from sex trafficking," said Nadeem Bezar, who along with two other lawyers announced the filing of the lawsuit Friday on behalf of the girl, identified as "M.B."

"There will be severe financial penalties for hotel and motels that allow these egregious acts to go on." — Nadeem Bezar, attorney

"There will be severe financial penalties for hotel and motels that allow these egregious acts to go on," Bezar told Fox News. "It's widespread. It's not just in Philadelphia."

The lawsuit is the first under a 2014 state law that allows sex trafficking victims to sue hotels and motels where abuse occurred.

The current federal statute allows for criminal prosecution of traffickers and, arguably, civil liability, according to legal experts, while the Pennsylvania state statute explicitly carves out a civil remedy. Pennsylvania is among a handful of states that provides for such civil remedies.

"The 2014 Pennsylvania statute allow hotels as a corporation to be held civilly liable for their involvement in sex trafficking," Bezar said. "Victims of the sex trade can bring a civil action against anyone who profits from the victim’s sex trade. As such, hotels face substantial risk if they rent rooms to traffickers.

The alleged sex trafficking of M.B. at the Roosevelt Inn began in 2013, when she was 14 years old.

According to the complaint, obtained by Fox News, the girl was lured to the motel where she was held against her will and forced to commit sex acts with about 1,000 men "double, triple and quadruple her age."

The traffickers who abused the teen were later arrested, convicted and imprisoned.

The motel's staff and management, meanwhile, knew the girl was being sexually abused but provided rooms to the traffickers who exploited her and forced her into prostitution, the lawsuit alleges.

The suit names the Roosevelt Inn in northeast Philadelphia, manager Yagna Patel and parent company UFVS Management in Purchase, N.Y.

Patel could not be reached for comment Tuesday. He told the Philadelphia Inquirer he has no knowledge of the girl in the suit or anyone being victimized in his motel.

Lawyers for the teen are dubious of such a claim, noting the many "Johns" who visited the motel, asking staff in the lobby for directions to the girl's room -- all of which was captured on security cameras.

The traffickers paid cash for the motel’s rooms being used to pimp the girl and consistently displayed "Do Not Disturb" signs on the door of the room, refusing housekeeping services, according to the suit.

A man working at the front desk, identified only as "Abdul," allegedly had conversations with the girl and knew she was staying at the inn to engage in commercial sex acts. The lawsuit claims he routinely directed men to the girl's room.

According to the National Human Trafficking Hotline, 7,572 human trafficking cases were reported in 2016 -- the majority of which involved sex trafficking. The state with the highest number was California -- with 1,323 cases reported last year -- followed by Texas, Florida, Ohio and New York.

Authorities say motels and hotels are common venues for traffickers to carry out their illegal enterprise -- and national statistics support that. Motels enable pimps to quickly move their operations with ease and avoid leaving a paper trail.

Mark Bederow, a criminal defense attorney and former New York prosecutor, said he supports the targeting of hotels knowingly engaged in such activity but said statutes, like that of Pennsylvania, can present legal challenges.

"Any hotel that permits or turns a blind eye to sexual trafficking that occurs on its premises should be held legally responsible for such conduct," Bederow said. "This lawsuit is a shot across the bow to those in the industry that bury their head in the sand about their complicity in such reprehensible conduct."

"On the other hand, not all abuse at a hotel is the fault of the hotel," he told Fox News. "The lawsuit could result in honest hotel owners 'interrogating' guests or monitoring guest activities in order to protect themselves from a similar lawsuit. It could lead to sincere owners, thinking about their bottom line, to act as surreptitious eyes and ears for the state out of concern they will find themselves in legal trouble — and possibly out of business — if they do not demonstrate their efforts to prevent sexual trafficking."

But in the case of the Roosevelt Inn, the motel blatantly ignored trafficked minors brought into its rooms over the years, according to attorneys for M.B. and law enforcement officials in the area.

Thomas Kline, another lawyer working the case, told the Philadelphia Inquirer he hopes the lawsuit will have a ripple effect nationwide.

"Jury verdicts will resonate with owners and operator of motel and hotels,” Kline told the newspaper. “There is no doubt that this is more commonplace than any of us would like to believe. This is an open, obvious, notorious case. But we also believe it occurs in fancy hotels in Center City, and occurs in casinos in our midst, and it occurs in shacks that are motels along the roadside. This is where the purveyors of sex traffic do their business.”