The families of Navy SEAL Team 6 members killed in a disastrous August 2011 helicopter crash in Afghanistan blamed the government for the tragedy, during an emotional press conference in Washington Thursday.

The family members, speaking at the National Press Club, tried to reopen the book on the crash, in which 30 Americans were killed, most of them belonging to the same unit as those who carried out the raid on Usama bin Laden earlier that year. The helicopter was shot down by insurgents.

During the event organized by a group called Freedom Watch, family members and former military personnel claimed President Obama turned the SEALs group into a Taliban target after the administration revealed they had conducted the bin Laden raid.

Doug Hamburger, whose son Patrick was killed, called the incident an “ambush” that could have been prevented.

“We’re very concerned that the administration had disclosed that the Navy SEALs had carried out a successful attack on bin Laden’s compound resulting in his death. And you know, never before in the history of our county (had) a sitting president released that type of information to the public, especially when he was talking about special forces. Their names and their missions had never been revealed before. And we really feel that this put our guys in an unnecessary risk,” Hamburger said.

Many military experts at the time, including some of Obama’s top military advisers, had questioned the White House’s public praise of SEAL Team 6 and said it put members in danger.

Three months after bin Laden’s death, members of the SEAL Team 6 force -- though apparently not the same ones who carried out the bin Laden raid -- were on board the CH-47 Chinook transport helicopter, along with its Army National Guard aircrew, several support personnel and seven Afghan commandos. In all, 38 people died that night after the chopper was shot down by a Taliban-owned rocket-propelled grenade –or RPG – over the Wardak Province on Aug. 6, 2011.

Charles Strange, whose son Michael, 25, died in the attack said Obama personally promised him a thorough investigation of what happened but has failed to deliver.

Strange also blamed top military brass for sending the troops into a situation they were allegedly ill-equipped and unprepared to handle. The team was responding to an Army Ranger unit that was engaged in a firefight with the Taliban and needed backup.

Asked for comment, Pentagon spokesman Lt. Col. James Gregory said: "We share in the grief of all of the families who lost their loved ones."

While not commenting directly on the allegations, he called those who were lost "warriors" who represented "the diversity and talent of America and its military."

An official report was released in October 2011 but family members say it did little to fill in the details and left more questions than answers.

Karen Vaughn says she wants to know why her son Aaron and his team were not using special operations aircraft which have defenses in place to help allow helicopters to go deep behind enemy lines. The night her son Aaron died, he was in a helicopter that was built in the 1960s and last retrofitted in 1985.