The police sealed the streets to most traffic, but the man in the tractor-trailer leaned out his cab window Wednesday afternoon, shipping papers in hand. His cargo was needed by the people working in the New York City medical examiner's office just across 30th Street, at 520 First Avenue.
"Body bags," he said, by way of explanation. "Four hundred and twenty-four cartons."
Asked how many were in a carton, he shrugged. It turned out there were 5,088 bags in the shipment; 900 more were delivered on Tuesday, the day of the attack. An additional 5,000 were due to arrive yesterday, according to the medical examiner's office.
The police cleared a path and waved him through.
A convoy of 10 refrigerated tractor-trailers that arrived from New Jersey Wednesday afternoon was parked along Second Avenue between 30th and 32nd Streets; they had space to store about 1,000 bodies.
From mass shipments of body bags to the microscopic inspection of body parts, New York is about to undertake the largest number of postmortem examinations in the annals of forensic medicine.
"The first step is, `Who are you?'" said Dr Charles Hirsch, the medical examiner. Yet even that could prove to be a step too far in many cases: so many victims suffered massive injuries that even the most sophisticated DNA testing may not be able to identify everyone, forensic scientists said in interviews.
Among the many unknowns in the terrorist attack on Tuesday is how many bodies the inferno burned beyond hope of recognition. Jet fuel burns at about 1,500 degrees Fahrenheit, depending on circumstances, about 200 degrees cooler than some house fires. Crematoriums heat the body to 3,000 degrees Fahrenheit for 30 minutes.
If a body burned at a very high temperature for only a few minutes before falling, tissue, hair and the pulp in teeth might still be useful for identification, said Dr Michael Baden, the forensic pathologist for the New York State Police.
A form of DNA testing has already identified several victims of the attack, New York City firefighters whose helmets and face and limbs were burned beyond recognition but whose torsos were left intact.