 Complete the following phrase:  Hendrikson was born into a workers family, graduated from primary school in 1910 and went to work as a student of a locksmith at a paper mill. Until 1918, he worked in several industrial plants, and from 1914 to 1918, he worked as a locksmith at the wagon construction workshop at Dvigatel. A member of the Estonian Communist Party since 1917, in 1918, when the German forces invaded Tallinn, he left with the Red Army on a war ship to Helsinki, volunteering to join the Baltic Fleet. He served in Kronstadt on the ship Respublika. He later fought in the 1918 Battle of Narva and the 