collapsed on March 31, 1923, shortly after one fully-loaded train had passed and just as another was approaching. In a separate incident, two passenger trains collided on the Maulua bridge on October 22, 1924; one train had stopped to disembark passengers, and the other had just emerged from the longest tunnel on the line. Passenger service over the Hāmākua line was provided by Hall-Scott motorcars pulling passenger trailers. In 1925, HCR ordered three railbuses from the White Motor Company to provide daily passenger service between Puna and Hilo, with a small turntable at Pahoa. Due to stiff competition from motor vehicles, the Glenwood extension was scaled back to Mountain View in 1926. By 1937, HCR had increased its network to of tracks, but Volcano service and the branch line from Olaa to Glenwood was abandoned completely on October 29, 1938. While the new Hāmākua line had been extremely expensive to build, and was costly to maintain, it was especially popular with tourists on HCR's Scenic Express service for ships calling at Hilo Harbor. Combined with regular passengers and traffic generated from the numerous sugar mills along the way, the HCR made great strides in paying down its debt. Increased revenue during World War II made the company more prosperous, and HCR was making a profit by the end of 1945. Tsunami and closure Ironically, just as the HCR was finally emerging from its long-standing financial troubles, it was hit with a blow from which it never recovered. On the morning of April 1, 1946, a massive tsunami caused by an earthquake in the Aleutian Islands struck Hilo and the Hāmākua coast, devastating the city and instantly wiping out a number of railroad bridges. Shareholders in HCR had already voted in March 1946 to discontinue rail operations. After the tsunami, the sugarcane plantations told HCR they intended to start shipping raw sugar to Hilo Harbor by truck; because the cost to repair the destruction was so massive, estimated at , HCR filed for abandonment soon after the tsunami, receiving permission from the Interstate Commerce Commission to do so as of December 31, 1946. Parts of the original Hilo Railway line southeast from Hilo to Ōlaa were taken over by the local sugarcane plantations, but those were soon abandoned for trucks after December 1948. HCR offered its entire right of way for the bridge-laden Hāmākua division without charge to the Territorial Government