Tear gas video triggers investigation into Navy SEAL selection course

[Tony]

Navy SEAL recruits on California's San Clemente Island were blanketed in a cloud of tear gas while being ordered to sing "Happy Birthday" so they couldn't hold their breath during training last year, according to a video obtained by CBS News. Exposure to tear gas is a standard part of SEAL training — but the video raised questions about how that training was carried out. 

The admiral in charge of Navy SEALs ordered an investigation when he saw the video. He told CBS News it raises questions about "the lawfulness of the behavior."