Historians estimate Onderdonk arranged to bring in six and a half thousand Chinese from China and many more thousand from California. The Chinese workers were assigned to crews separate from the white workers and often given the most dangerous jobs, including the tunnel blasting, using the highly unstable nitroglycerin explosive. Many Chinese were killed in accidents or died of scurvy during the winter. Scurvy fatalities, due to a vitamin deficiency in the diet, were high because of the workers' dietary reliance on rice. They were given rice mats as part of their pay system, and the workers had little cash to buy supplements for their food. They owed debts to the Chinese labour contractors who had sold their services to Onderdonk. Unlike the white workers, injured Chinese workers were not provided access to the company hospital. They were left to the aid of their fellow workers. At the end of construction, the Chinese labour contracting companies abandoned their charges; thousands of workers were left stranded and living in caves without food and water in the desert heat of the mountains surrounding Spences Bridge. They were not able to leave the area until white charities in Vancouver sponsored tickets for their transport back to China or California.