Foreign rescue crews, declaring their work finished, are leaving Mexico as U.S.-led demolition teams set up shop and the government tries to take stock of the loss in lives and property from last week's killer earthquake.

In a directive last night, President Miguel de la Madrid ordered government rescue squads to assign "the highest priority" to sites where even slight hope remains of unearthing survivors buried in the rubble. More than 1,600 persons, including at least 40 infants, have been pulled alive from the wreckage in the past week, according to official reports. Yesterday another four were saved.

At the U.S. Embassy, meanwhile, the number of Americans confirmed dead in the Sept. 19 earthquake rose to 10 today as spokesman Lee Johnson reported that Ivan and Iriada Ducos, a Puerto Rican couple, had died in the Hotel Romano. The embassy also confirmed the death of Emery Pakas of Huntington Beach, Calif. Not all the dead Americans have been publicly identified. More than 20 U.S. citizens said by relatives and friends to have been in the downtown area at the time are still missing and the majority are presumed dead, U.S. officials said.

Desperate efforts to locate more survivors continued in at least three locations. American and Israeli experts worked to free two persons from the ruins of a collapsed downtown building, while searchers probed a destroyed garment factory where one woman was rescued yesterday.

At the Juarez Hospital, where some rescue workers said as many as 80 infants may remain alive, conflicts persisted between foreign rescue personnel and Mexican military authorities. International experts opposed to the introduction of heavy equipment at the site were overruled by the Mexican Army yesterday afternoon, which, despite protests, began bulldozing a section of the wrecked hospital.

Mexican officers later heeded a request to halt the machinery from U.S. Ambassador John Gavin who "intervened" on behalf of Dade County, Fla., firemen working at the site, embassy spokesman Johnson said today.

But hope is fading, Mexican and foreign officials concur. Health Minister Guillermo Obregon ordered yesterday the fumigation of all earthquake debris. U.S. demolition experts, meanwhile, inspected about 30 quake-damaged buildings that may be demolished with explosives in what would be the first such use of that technique in Mexico.

The demolition will proceed "without haste" and "with proper respect for the dead," said Alan Hooper of Columbus, Ohio, one of five U.S. demolition specialists donating their services.

The total number of earthquake victims is not yet known, with the frequently conflicting official estimates now ranging from 4,000 to 9,000. City police officials reported last night that 5,600 bodies have now been recovered, while federal Interior Ministry officials said fewer than 2,000 have been extricated from buildings ruined in the quake.

In addition, more than 4,000 persons who were reported missing by relatives and may have been visiting or living in the earthquake zone remain unaccounted for, reported Locatel, a Mexican government missing persons agency.

Damage also has yet to be precisely quantified. Replacing the more than 700 destroyed buildings would cost in excess of $2 billion, one national university expert estimated. But a spokesman for the National Association of Insurance Adjusters, which plans to release a detailed report on the earthquake damage in two weeks, said it would be "sheer science fiction" to release an estimate at this stage.

Insurance costs will rise if it can be demonstrated that contractors flouted the city's strict antiseismic building code. But some experts say the sheer force of the earthquake -- upgraded by scientists to 8.1 on the Richter scale -- will make it difficult to prove that the destruction was caused by negligence.

"I have looked at about 80 apartment buildings that were destroyed, and in not a single one could I say that the damage was due to the use of crummy materials," Mete Sozen, a construction expert here with a U.S. National Academy of Sciences team, said as he concluded a week-long inspection of the earthquake damage today.

For the federal government alone, the cost of rebuilding collapsed or damaged offices could easily exceed $1 billion, most experts say.

The interruption of government services already has meant economic disruption. The powerful Commerce and Industry Ministry, its Mexico City headquarters and computer center now ravaged beyond repair, is now hand-processing export and import permits across town in the Foreign Trade Institute's underutilized office tower.