The ensuing air strike, five minutes later at about 4.30am local time, demolished a large part of the structure, starting a fire and leaving two dead and four others horrifically injured from shrapnel and burns.
As the victims were carried out of the ruined building in Beit Lahia, the mood was one of despondency and anger.
One body was that of 42-year-old Soha Abu Sada, who lost a leg in the blast. She was wrapped in a blanket and carried out by young men chanting, "Allah hu Akhbar."
A woman in a black chador, Abu Rashida, a distant relation, cried: "This is the fate of our people, even those who are already suffering must suffer a terrible death."
The centre for the disabled had been in Gaza for 24 years, and survived many episodes of strife between Israelis and Palestinians.
The organisation moved to the present location three years ago, and a neighbour claimed that a member of Islamic Jihad (the militant Palestinian group) and his family had also once lived in the building, although he was not sure of their current whereabouts.
This was firmly denied by those who ran Mobarat Felestin.
Israelis on a hill at the Israeli town of Sderot, overlooking the Gaza Strip, watch smoke rising following an Israeli strike on Gaza yesterday. Photo / AP
Among other targets hit by Israeli warplanes was the al-Farouq mosque, which was left with just its minaret standing. Hamas threatened retribution and claimed the destruction would galvanise support across the Muslim world.
"The bombing shows how barbaric this enemy is and how much it is hostile to Islam," declared spokesman Hasam Badran. "This terrorism gives us the right to broaden our response to the occupier."
The Israeli Government, however, issued satellite photographs which, it stated, showed that the mosque, near the Nuseirat refugee camp, was being used to store rockets. It charged that Hamas and Islamic Jihad systematically used "mosques to conceal weaponry and establish underground tunnel networks, abusing the holy nature of these sites for their own terror-oriented agenda".
The Israeli Ministry of Defence announced that an inquiry would be held into the attack on the home for the disabled. But to Salwa Abu-Alkhorsan, lying on her bed at the Shifa Hospital in Gaza City, swathed in bandages, that meant nothing: "The Israelis know they can say anything they like. All I know is that I am in such pain. I did not know such pain existed."
The 53-year-old helper at the centre had prepared the suhoor meal and was preparing to pray when she was sent flying by the explosion.
"I could see fire all around me, then I knew I was on fire. I started running to get out, but then I fell," she recalled. "I have heard what had happened to the others and I feel so sorry for them. They cannot look after themselves and to be caught up in this was so bad. None of us thought this would happen, I thought I was safer working there than anywhere else, I thought all the others were safer there than anywhere else."
The number of casualties could have been more at Mobarat Felestin; 12 of the residents had gone home for the weekend, the five who stayed behind had no families to go to.
The two dead were 30-year-old Ola Ushahi and Soha Abu Sada. The survivors, who all suffer from cerebral palsy, are seriously ill. Sally Saker, 18, has head and neck injuries and 18 per cent burns; Mai Hamada, 31, with a severe torso injury, has 25 per cent burns; and Ahmed Al-Awar, 26, with head and neck injuries, has 11 per cent burns.
Watch: Raw: Israel, Gaza exchange rocket fire
Jamilla Alaiwa, a 59-year-old social worker who founded the home in 1990, was adamant there were no paramilitary links.
"We are not involved in politics and there is nothing there which justifies this action by the Israelis. We all know they don't need any reason to do things like this, they are a paranoid people.
"The building was rented, and tomorrow I will start looking for another place, so that those who were safe in their family homes when this happened will have somewhere to come to. We will also have to find a way to look after those who are in hospital and survive."
Dr Raid Nawas, a 27-year-old plastic surgeon who is part of the care team, said: "We will have to wait for the next 24 hours to see if they make progress. At the moment it is a matter of keeping them alive: things like grafting for the burns is in the future.
Nawas, who had been on duty for 26 hours, was about to go home when a call came from his family. Their neighbourhood was being heavily bombed and he was safer staying in the hospital, they insisted. "Let's hope so," he shrugged. "Who knows nowadays?"
Iron Dome safety comes at a hefty cost
On the outskirts of the Israeli city of Ashkelon, two state-of-the-art anti-missile defence batteries stand on high alert.
Shaped like two giant match boxes tilted diagonally towards Gaza, the system comes to life as the wailing of a siren echoes through the nearby loudspeakers.
In the time that it took to read the two sentences above, the Iron Dome system will have determined whether the rocket soaring through the sky is likely to land in an open field or crash into a building in a city.
An Iron Dome system fires to intercept a rocket from Gaza in the Israeli city of Ashkelon. Photo / AP
In the case of the latter, a counter-missile will already have been deployed to intercept it.
At least 800 rockets have been launched at Israel from Gaza in the past week. Of these, the Iron Dome has intercepted at least 130.
The system, designed and built by Rafael Advanced Defence Systems in 2011, is configured to only destroy the rockets poised to hit urban or strategically sensitive areas.
Each interception missile fired is priced at US$50,000 ($56,734). In the war with Gaza in November 2012, the Iron Dome blocked almost 500 rockets - a total cost of US$25 million.
There are seven Iron Dome batteries deployed around the country, and so far they have had an almost 90 per cent interception success rate.
The Iron Dome is susceptible to occasional failures. In the 2012 war, an error resulted in a rocket crashing through the walls of a house in Kiryat Malachi, southern Israel, killing three people. Rafael said the system has since undergone significant improvements.
How the Iron Dome works
1 Its radar detects a rocket, sends information about it to the Iron Dome battery control centre
2 The centre works out if the rocket will hit populated areas
3 If the rocket is a danger, one of 20 missiles is fired from the launcher
4 The missile is guided by the control centre and its radar
5 The missile destroys the rocket by exploding near it
Air strikes take heavy toll on Gaza
165 Palestinians at least have been killed, says Gaza Health Ministry
1060 Palestinians wounded, the ministry says
0 Israelis killed, 10 injured by rockets that slipped through
4 Israeli soldiers hurt in clashes during brief ground operation to destroy rocket launching site in northern Gaza
1300 air strikes over six-day offensive
800 rockets and mortars at least fired overall at Israel
130 incoming rockets intercepted by the Iron Dome defence system
- Independent, Telegraph Group Ltd, AP
