Economic recovery in the early 20th century was caused by the silk and textile industry. The Adelaide Silk Mill, which was one of the biggest mills in the world, opened in Allentown in 1881. By 1928, there were more than 140 silk and textile mills in the Lehigh Valley which made silk the second biggest industry. By the 1930s, the silk industry was getting slow in all the world because synthetics were taking the place of silk. Catoir Silk Mill, the last silk mill in Allentown, closed in 1989. In 1905, Mack Trucks moved to Macungie, a small suburb of Allentown, which began Allentown's focus on big industrial manufacturing. Today, Allentown's economy is mostly service industries.