In the Spanish–American War of 1898, Mayagüez welcomed U.S. troops who occupied it on August 11 without a fight. The college that later became the University of Puerto Rico at Mayagüez opened in 1911. Severe destruction again occurred in the 1918 San Fermín earthquake. During the later 20th century the city developed a large-scale export trade to the U.S., based on tuna processing and textiles.