American Football Rules IFAF Approved Ruling 8-5-1:III

III. B1 intercepts a legal forward pass (not a try) deep in his end zone, and advances but does not get out of the end zone, where he is downed. During the run, B2 clips A1 in the end zone. RULING: Safety, since the penalty leaves the ball in Team B’s possession in the end zone. [Cited by 8-5-1-b]