Police and firefighters on Monday were investigating the cause of a gas explosion in a Jerusalem building that killed a couple and their 2-year-old child. Residents of the building said they had been complaining of problems with the gas system for many months, with no adequate response from the gas company Supergas.

Building resident Meir Kadosh said the building had been plagued with gas leaks for over a year, due to what he called a faulty and poorly constructed system. Kadosh told Army Radio that residents had sent a letter of complaint to Supergas months ago, but that the problems had not been dealt with.

Police were investigating whether a Supergas technician, who had been called to the building to check on a gas leak around 10 p.m. on Sunday, had been negligent in his work. A spokesman for Supergas said the technician had been called twice to the building on Sunday and had turned off the gas. Residents said the technician had promised to return in the morning and told them that the problem was temporarily taken care of. When they complained that they still smelled gas, he reassured them that the odor would go away.

The explosion occurred just after 1 a.m. on the third floor of the four-story building on Shabtai Hanegbi Street, in the Gilo neighborhood in the southern part of the city, causing it to collapse partially. Several apartments were heavily damaged and 11 other residents were injured. A woman in her 50s was in critical condition and an octogenarian couple suffered moderate injuries. Most of the other injured residents had been released from hospital by noon Monday.

The victims of the blast were named as Avraham and Galit Tufan, 56 and 42 respectively, and their 2-year-old son, Yossef Haim.

Rescue and medical personnel at the scene of a gas explosion that killed three people in Jerusalem's Gilo neighborhood, early Monday morning, January 20, 2014 (photo credit: Yonatan Sindel/Flash90)

Rescue and medical personnel at the scene of a gas explosion that killed three people in Jerusalem’s Gilo neighborhood, early Monday morning, January 20, 2014 (photo credit: Yonatan Sindel/Flash90)

The technician was arrested in the early morning hours and a court remanded him until Wednesday. His lawyer, Yehuda Shoshan, said that he was a veteran worker who had been with Supergas for the past 17 years. Shoshan claimed that the explosion must have been the result of a second leak, not the one treated by his client. “The technician could not have known that there was a second leak,” he said.

The blast echoed throughout the capital, even in neighborhoods several kilometers away, and building residents and eyewitnesses described a harrowing ordeal.

“Glass exploded onto me [as I slept],” one resident told Army Radio. “My girls were traumatized. I checked to ensure they weren’t injured. They were hysterical.” Another resident told Channel 2 news that he had initially feared a terror attack, or even a missile strike, when he felt the explosion.

Paramedic Fadi Badarna told Army Radio he pulled the critically injured toddler out of the wreckage and treated him before he died en route to hospital. “It was a very difficult scene. The house was badly damaged. Everything was torn apart inside — it’s indescribable,” he said.

In a statement, Supergas said it was cooperating with police in its investigation of the incident and expressed sorrow for the loss of life. The gas company noted that the building’s gas pipes had been inspected as required by law and found to be in satisfactory condition.

“According to the law, a test of the building’s main gas system is required every five years. In the building [in question], a test was conducted in September 2012 and the system was found to be in order,” the statement read.

Lazar Berman contributed to this story.