Aug. 6, 2011 -- A helicopter was shot down today by Afghan insurgents as it was rushing to aid troops in a firefight, killing 30 Americans, including 22 Navy SEALs, most of whom belonged to Team 6, the unit whose members were involved in the raid that killed Osama bin Laden, U.S. officials said.
The Chinook helicopter was carrying a quick-reaction force to provide back-up to the troops on the ground in the eastern Afghan province of Wardak, a U.S. official said. After the crash, the forces that were involved in the firefight "broke contact" with the enemy so they could go provide perimeter security for the crash site, the official said.
Additional forces were then sent to secure the crash site.
It's unclear how far away the helicopter was from the initial firefight when it went down and unclear how the troops in the firefight got to the crash location, the official said.
In addition to the 30 Americans, the official said there were seven Afghan army soldiers and an interpreter on the helicopter.
Although the Taliban have claimed to have shot the helicopter down, U.S. officials have only identified the attackers as insurgents.
On July 25, a Chinook was hit by a rocket propelled grenade fired by the Taliban. It launched in the belly of the aircraft which made a hard landing and only two soldiers were injured in that attack but this time all on board were killed.
Saturday's deaths bring the total number of coalition troops killed in Afghanistan to 334 this year, according to the Associated Press.
The last worst one-day U.S. casuality record in Afghanistan was on June 28, 2005 when 16 U.S. soldiers were killed in Kunar province after a helicopter was shot down by Taliban insurgents.
Afghan President Karzai's office released a statement on the incident.
"A NATO helicopter crashed last night in Wardak province," Karzai said in the statement. "President Karzai expressed his deep condolences because of this incident and expressed his sympathy to Barack Obama."
President Obama offered his thoughts and prayers to those killed in the crash.
"Their deaths are a reminder of the extraordinary sacrifices made by the men and women of our military and their families, including all who have served in Afghanistan," Obama said in a statement. "We will draw inspiration from their lives, and continue the work of securing our country and standing up for the values that they embodied. We also mourn the Afghans who died alongside our troops in pursuit of a more peaceful and hopeful future for their country. At this difficult hour, all Americans are united in support of our men and women in uniform who serve so that we can live in freedom and security."
The Associated Press contributed to this report.