A small fire at the temporary home for the remains of thousands of World Trade Center victims was likely arson committed after a break-in on Saturday, authorities said.

The smoldering flames in a section of the facility's chapel on Manhattan's East Side were quickly extinguished.

Firefighters got a call at about 9 a.m. to respond to Memorial Park, a weatherproof tent on Manhattan's East Side where the city is storing the remains of 9/11 victims who have yet to be identified.

The fire damaged a wooden bench, while mementos — pictures, notes, flowers — honoring the dead disappeared.

"Anyone who would set fire to the inviolable Memorial Park chapel is craven and contemptible," Mayor Michael Bloomberg said in a statement.

Fire marshals and police were investigating.

Nazli Parvizi, the mayor's community affairs commissioner, sent 9/11 families an e-mail informing them of the incident. Sally Regenhard, whose son perished at the World Trade Center, forwarded the statement to The Associated Press.

Parvizi told the families that about an hour before the fire started, a break-in was discovered in the chapel. Memorial Park is near the city medical examiner's office, which created special photo IDs to be used by families to enter the site.

Authorities were unsure whether the mementos had been stolen or burned, "but little remains inside the chapel," said Parvizi, adding that the structure showed some smoke damage.