The shooting at a gay nightclub in Orlando early on Sunday has reignited congressional debate over terrorism and the country’s gun laws, as lawmakers grappled with responding to one of the deadliest shootings in U.S. history.

Congressional leaders, including House Speaker Paul Ryan (R., Wis.) and members of the House and Senate intelligence committees, were briefed on the attack Sunday.

“We pray for those brutally attacked in Orlando,” Mr. Ryan said on Twitter. “While we must learn more about the attacker, the victims [and] families will not be forgotten.” Mr. Ryan called for flags flying over the Capitol to be lowered to half-staff.

Law-enforcement officials were still working to understand the motive behind the shooting that left 51 dead and 53 injured at Pulse, a gay nightclub in downtown Orlando. Police shot and killed the alleged gunman, identified by counterterrorism officials as Omar S. Mateen,who worked as a security guard, had a gun license and was a U.S. citizen. Officials said there are some initial indications the shooter was attracted to radical Islamic ideology.

Congressional leaders said they were waiting to hear more details about what prompted the shooting. The details likely will shape the debate in Congress.  wsj.com