(CBS/AP) NEW YORK - Authorities will resume digging up the basement of a New York City building Monday in connection with the disappearance of 6-year-old Etan Patz, who went missing on his way to the school bus in 1979.
The search of the lower Manhattan basement, which began last Thursday, was set to start up again at 8 a.m. Monday after it was suspended for "operational reasons," according to an FBI spokesman.
CBS New York reports FBI agents suspended the search Sunday, in part because of the weather. However, FBI spokesman Peter Donald would not discuss the reasons behind the search's suspension. "We'll be back in the morning," he said.
According to the station, investigators came up with a section of the wall showing a "stain" that is now headed to an FBI lab in Virginia. This is where it will be tested to determine if it is human blood.
"People who try to clean up crime scenes and leave this invisible blood behind, that's revealed by luminol spraying," explained forensics expert Dr. Lawrence Koblinksy.
CNN reports that on Sunday around 2 p.m., authorities searching the basement suddenly folded up a tent that had erected to protect them from a nor'easter weather storm that was slamming the east coast.
Minutes later, two large NYPD vans pulled up, and according to CNN, photographers were able to see something being loaded into the side of an unmarked van.
Investigators are still looking for any traces of Patz. He would have passed the stairwell leading to the basement being searched during his walk to the bus stop from his SoHo apartment.
"Fundamentally, it's about going through dirt, sifting, going carefully and looking for evidence," said Jim Margolin with the FBI. "We'll be done when we're done."
Excavation of the SoHo basement is reportedly halfway finished and should be completed Monday.
Police say they began the search after an FBI dog indicated the scent of human remains in the room. The basement was used at the time of the boy's disappearance as a workspace for a handyman named Othniel Miller. He was interviewed after Etan's disappearance in 1979. He has not been named a suspect.