Soot-marks smeared against the wall, a trail of blackened footprints, and a half-charred door were all that remained yesterday as visible reminders to tenants of 104 Ross St. of the fire Monday that claimed the lives of three boys, leaving a tight-knit Jewish community in South Williamsburg to mourn during the Passover celebration.

More than a day after the flames engulfed the Matyash family’s apartment, injuring 10 other people, including two sisters who leaped from the second-story window, questions lingered as to what caused the fire and whether it could have been prevented.

Fire officials determined Monday that the fire originated from an open flame on the apartment’s stovetop, left on through the weekend, but some family relatives and neighbors have begun to dispute that conclusion.

A relative of the mother of two of the boys who died and the grandmother of the third boy, Rachel Matyash, said the family had the burners turned off before going to sleep Sunday night. Ms. Matyash told the relative, who asked to be identified only by her first name, Anna, that a home attendant from across the hall had come over to turn off the burners, shortly after the family completed the second Passover seder.

The home attendant’s employers, who live across the hall from the Matyash family, agreed that the attendant left around 3:30 a.m. to turn off the stovetop.

Other tenants in the building said it was not uncommon for Passover observers to ask non-Jews to extinguish flames for them on the Sabbath or other days of rest. On this night in particular, the home attendant’s employers said, she was asked by several families to help with that task.

Officials of the Fire Department said, however, that they received a different account from the attendant, one confirming their initial determination that the fire originated from an open flame, which ignited a wood panel behind the stovetop.

“The home attendant was instructed by a visiting relative to turn off one burner and leave the other on,” a spokesman for the department, Francis Gribbon, said. He also said the home attendant gave the eyewitness statement to investigators hours after the blaze was brought under control.

Mr. Gribbon said the investigation of the fatal fire is continuing but the blaze has been classified as accidental.

Other tenants have complained that the building lacked working smoke detectors.

A neighbor living two doors down from the Matyash family said she learned of the fire when she saw smoke filling the hallway shortly before 6 a.m. She took off her shoe and used it to bang on doors down the hallway. The smoke alarms had not sounded.

“If it weren’t for that woman, we would have all been killed,” the tenant at 2H, who declined to be identified by name, said yesterday.

Ms. Matyash later told family members she had awakened to the smell of smoke seeping under her bedroom door. Upon opening the door, she found herself engulfed in flames.

She had not heard the smoke alarms go off, or the carbon monoxide detector, which had been installed several months ago, the relative named Anna said.

According to the Fire Department, smoke detectors were present at the building, but fire officials were unable to determine whether they were working, because detectors are often damaged during the fire. They did confirm that residents said the smoke alarms did not go off during the fire.

Building inspectors also visited the Bedford Gardens apartment complex yesterday to evaluate any structural damage and concluded there was none. They also did not find any building violations related to the fire.

A spokeswoman for the Buildings Department, Jennifer Givner, said it is not uncommon for buildings to lack central fire alarm units. She also said Kraus Management, which runs the building, had received no prior citations for 104 Ross St., although tenants have filed complains about the elevator.

The Buildings Department did receive seven complaints today from tenants of the building, some asking why sprinklers had not been installed.

Ms. Givner said those complaints would be reviewed by department. She said the building’s age and construction type would determine whether sprinklers were required.

Some tenants interviewed at the building yesterday faulted the window bars for trapping the Matyash family in the apartment.

Window bars are legally required by the city in buildings that have tenants 10 and under, and do not have fire escapes at the windows.

The building manager of Bedford Gardens, Stephen Kraus, noted that window bars cover only one side of the windows. The other side, made of Plexiglas, can easily be broken, he said.

The funerals for the two teenage boys who died in the fire – Yidel Matyash, 13, and his brother, Shiya, 16 – were held late Monday night after their father, Symah Matyash, was released from Long Island College Hospital at Cobble Hill.

The funeral procession, which started at a funeral chapel at Broadway and passed the family’s synagogue at Rodney Street, was attended by hundreds, relatives said.

Anna said Ms. Matyash, grieving over her deceased sons, had whispered to the coffins, asking for forgiveness and telling the boys to pray for the family.

The brothers were buried within 24 hours of their death, in accordance with Jewish practice.

The third boy who died, their nephew Israel Falcowitz, whose age was variously reported as 6 and 7, was buried earlier Monday.

Gitty Matyash, 18, was released from the hospital late Monday and attended her brothers’ funeral on crutches. Her ankle had been broken in the 15-foot fall. Her sister Sara, 21, who was more seriously injured, was transferred by ambulance to New York Hospital-Cornell Medical Center, to undergo reconstructive surgery on one of her legs, a relative said.

Yesterday, the medical examiner’s office attributed the three boys’ deaths to smoke inhalation.