http://www.politifact.com/truth-o-meter/statements/2014/may/12/john-garamendi/prior-benghazi-
were-there-13-attacks-embassies-and/
We searched the database for descriptions between January 2001 and January 2009 that included the term "U.S. embassy." We supplemented these with a few other attacks listed in a Huffington Post opinion piece that Garamendi’s staff said was their main source for the claim. The Huffington Post column Garamendi cited purposely didn't count any attacks in Baghdad. So we decided to construct our count from scratch.
While Garamendi spoke of "embassies and consulates," we found several U.S. diplomatic targets killed in the line of duty outside official compounds -- such as in convoys or their homes -- and we included them in our count. Once we cross-referenced the attacks in the article and those in the database, we narrowed down the total to 39 attacks or attempted attacks on U.S. embassies and embassy personnel.
Of these 39 attacks, 20 resulted in at least one fatality. (Our complete list is here.) This is higher than Garamendi's claim, though if you only count attacks on embassy and consular property, there were 13.
Garamendi also understated the number of deaths. In the 20 incidents with at least one fatality, the total death toll was 87 -- quite a few more than the 60 Garamendi cited. If you only count those at embassies and consulates proper, the number of deaths drops to 66.
We should note that the vast majority of these deaths were not Americans. We counted 63 deaths that were either of non-Americans or of people whose nationality is unknown. Another three were U.S. civilians. Another 21 were workers at the U.S embassy or consulate, either of American or foreign nationality.
So, using what we think is the most reasonable definition, Garamendi's numbers are a bit low.