In addition to passengers, what was the Lusitania was carrying when it was sunk?

In addition to passengers, the Lusitania was also carrying more than 170 tons of war munitions for the United Kingdom. The munitions included more than 4 million rounds of rifle ammunition, more than 1200 cases of shrapnel shells, and about 18 cases of non-explosive fuses. 
The Lusitania was also said to be carrying priceless paintings as well. Accordingly, the art collector Sir Hugh Percy Lane was on board the ship. He was traveling with Charles and Frances Fowles, fellow art collectors. It was rumored that Sir Percy Lane had masterpiece paintings by Rubens, Monet, and Rembrandt on board the Lusitania. These paintings were stored in 27 circular containers. Today, it is widely believed that the paintings sunk along with Sir Percy Lane (his body was never recovered).
Although the paintings were priceless artifacts, they were not the reason the Lusitania was sunk by the Germans. Because Germany suspected that ships sailing west might be carrying war munitions, it unleashed unrestricted submarine warfare on them. The German military leadership believed that the sinking of passenger ships would cause the English and the French to surrender. Instead, the sinking of the ships strengthened Allied resolve and prompted the Americans to enter the war.
https://www.history.com/news/the-sinking-of-rms-lusitania-100-years-ago

https://www.history.com/topics/world-war-i/lusitania