Fred Bailey Richardson, 72, died at Loma Linda University Medical Center, authorities said.
Richardson, who ran a landscaping business, was towing a trailer full of equipment when his truck was struck head-on Sunday evening on Highway 38 near Yucaipa by the bus, which was returning a group to Tijuana, Mexico.
Richardson was returning to his century-old stone house in unincorporated Mentone, the Los Angeles Times (http://lat.ms/YDClDv) reported.
Richardson worked on many of his neighbors' yards in the tiny mountain community and was well-liked, Carly Schmitt said. She told the Times that Richardson, who had two grown children, was an avid trout angler and his wife grows African violets.
"The night it happened, I was just watching TV, just bawling my eyes out," Schmitt said of the crash.
Seven other people on the bus died after it struck a sedan, flipped, slammed into the pickup and crashed while heading down the road in the San Bernardino Mountains east of Los Angeles. The crash littered the area with wreckage and body parts.
Dozens were injured and several remained in critical condition.
The roadworthiness of the 1996 bus loomed as a key issue after the driver told investigators the brakes failed as he descended the two-lane highway. Federal records pointed to a history of brake-maintenance problems with the European-made bus.
Road conditions and possible driver error or fatigue also were being considered.
The bus, operated by National City, Calif.-based Scapadas Magicas LLC, was carrying 38 people, including the driver and a tour guide, when it left Tijuana at 5 a.m. Sunday for the daylong trip. The accident occurred around 6:30 p.m.
No one answered the phone Wednesday at Scapadas Magicas' Tijuana office or at a listing for its National City address.
The accident killed San Diego residents Guadalupe Olivas, 61; her daughter, Elvira Garcia Jimenez, 40, and her grandson, Victor Cabrera Garcia, 13.
The trio was part of a group of five employees of a Tijuana health clinic and four of their family members, said Dr. Carlos Sanchez, director of the clinic, which is known by its Spanish acronym Issstecali. The tight-knit group went to see snow.
Garcia Jimenez was a part-time doctor at the Tijuana clinic since October 2011, Sanchez said. Two others in the group—another part-time doctor and a receptionist—remained hospitalized Wednesday with serious injuries.
Also killed were Tijuana residents Aleida Adriana Arce Hernandez, 38; Rubicelia Escobedo Flores, 34; Mario Garcia Santoyo, 32, and Liliana Camerina Sanchez Sauceda, 24.