It was eleven years ago when Danielle Imbo and Richard Petrone, Jr. were last seen enjoying a night out on Philadelphia's South Street.
The investigation that followed involved officials from two states and the FBI, but after more than a decade no one has been able to answer the question of what happened to the New Jersey couple.
Now on this somber anniversary, investigators are once again asking the public for their help in solving the cold case.
Imbo, 34, and Petrone, 35, were old friends who once dated who went to Abiline -- a now defunct bar and restaurant along South Street -- on February 19, 2005. It would be the last time anyone saw them.
Their cellphones and credit cards weren't used after the disappearance, said investigators.
Family and investigators describe the couple as stable. Both have children from previous relationships and held good jobs.
Family members believe the duo were killed. Officials have said the two may have been the victims of a murder-for-hire plot, but will not say why. The couple has been pronounced dead but it's not clear how they died.
Authorities have pursued hundreds of leads and listened to thousands of tip calls. Searches were conducted on the ground and by air, and waterways were combed. The nature of the crime has led investigators to conclude it was a planned attack acted out by more than one person.
Petrone’s black 2001 Dodge Dakota pickup truck was also never found.
On Friday, the FBI said the case "remains open and active, and there is a $50,000 reward for information about the couple’s whereabouts or for information leading to the arrest of those responsible for their disappearance."
Anyone with information is asked to call the Citizens Crime Commission tipline at 215-546-TIPS (8477). Tipsters can remain anonymous.