The White House is now saying it is clear that Syria used chemical weapons, including sarin nerve gas, on its own people, killing as many as 150 rebels.
The big question being asked now is how forcefully will the White House respond? Barbara Starr is following the developments.
"Pressure is growing on president Obama to act," Starr says. “The White House says it will boost military support to the rebels, but won't say exactly how.” Arming the rebels may be an option, Starr reports.