At 05.20 hours on 8 July 1943, U-510 fired three torpedoes in one minute intervals at convoy TJ-1 and reported hits on three ships. At 07.19 hours, the U-boat fired five more torpedoes and claimed hits on two further ships. At 13.07 hours, U-510 attacked convoy again and reported another ship of 6000 tons sunk. However, Allied sources only confirm hits on three ships: B.P. Newton, Eldena and Everagra, which was only damaged. It seems that the U-boat attacked the same targets several times.

At 05.21 hours, the Eldena (Master Charles Clinton Bently) in station #43 was hit by one torpedo on port side in the forepeak. The explosion breached the collision bulkhead and flooded the #1 hold. The eight officers, 32 men and 26 armed guards (the ship was armed with one 4in, one 3in and eight 20mm guns) abandoned ship in four lifeboats as the ship settled by the head. Most of the survivors were picked up by USS PC-495. One hour after the attack, the master and 16 crewmen in the second lifeboat reboarded the ship and started the engines and pumps. She was proceeding at just over four knots, when she was hit at 07.33 hours by a torpedo from the second attack by U-510. The torpedo struck one the starboard side at the #2 hatch. The explosion threw water 35 feet in the air and she sank within minutes, leaving large quantities of her deck cargo, including aircraft parts in waterproof crates on the surface. USS PC-495 picked up all hands and landed them in Recife, Brazil on 17 July.

Eldena had left New York on 11 June in convoy NG-367, Guantanamo on 18 June in convoy GAT-69 and Trinidad on 3 July in TJ-1.