 The US Embassy , Saigon , a massive six @-@ floor building situated within a four @-@ acre compound , had only been completed in September . At 02 : 45 it was attacked by a 19 @-@ man sapper team that blew a hole in the 8 @-@ foot @-@ high ( 2 @.@ 4 m ) surrounding wall and charged through . With their officers killed in the initial attack and their attempt to gain access to the building having failed , the sappers simply occupied the chancery grounds until they were all killed or captured by US reinforcements that were landed on the roof of the building six hours later . By 09 : 20 the embassy and grounds were secured , with the loss of five US personnel . 
