US President Barack Obama has addressed the Connecticut town devastated by the massacre of 26 people, including 20 young schoolchildren, lauding residents' courage and saying that the US was not doing enough to protect its children."We bear a responsibility for every child ... This is our first task, caring for our children. It's our first job. If we don't get that right, we don't get anything right," Obama told a packed auditorium at Newtown High School at the end of a sombre multi-faith service."Surely we can do better than this," he said.The emotional prayer vigil capped a day when worshippers sought solace in churches to mourn the victims of Friday's slaughter at Sandy Hook Elementary School in Newtown, where a gunman used a military-style assault rifle to kill six adults and 20 first-graders before committing suicide.A more detailed picture of Adam Lanza’s stunning attack emerged on Sunday. Police said he was armed with hundreds of bullets in high-capacity magazines of about 30 rounds each for the Bushmaster AR-15 rifle and two handguns he carried into the school, and had a fourth weapon, a shotgun, in his car outside.All the dead children were either six or seven years old, feeding more emotion into a revived debate about whether stricter gun laws could prevent future mass shootings in the United States"Can we say we’re truly doing enough to give all the children of this country the chance they deserve to live out their lives in happiness and with purpose?” the president asked, as many in the audience wept."If we’re honest with ourselves, the answer is no.”‘Preventing more tragedies’Obama pointed out that this was his fourth memorial service for a mass shooting since coming to office in 2009. He also pointed out the number of killings happening on a regular basis in towns and cities across the US."In the coming days, I’ll use whatever power this office holds to engage my fellow citizens, from law enforcement to mental health professionals to parents and educators in an effort aimed at preventing more tragedies like this.”Several Democratic lawmakers called for a new push for US gun restrictions on Sunday, including a ban on military-style assault weapons.Senator Dianne Feinstein of California, the author of an assault-weapons ban that lapsed in 2004, said she would introduce new legislation this week.Gun rights advocates have countered that Connecticut already has among the strictest gun laws in the nation.