The accident that killed six Mexican nationals Monday was the worst involving undocumented immigrants in Colorado in recent memory. At least 12 other passengers in the van were still in Colorado and Nebraska hospitals Monday night, with several victims in intensive care. View the wreckage from the crash Interstate 76 and other highways in Colorado are the new pipelines for smugglers who've been feeling the heat lately along the U.S.-Mexico border, 7News reporter Hendrik Sybrandy said. The smugglers believe that Colorado is the best way to get their human cargo deep into America, Sybrandy said. Smugglers prefer highways like I-76, which is a road less traveled and less patrolled by immigration agents. The Immigration And Naturalization Service believes that that's why the van was on I-76. "Most times the vehicles originate in the desert, they don't have snow tires, the smugglers have very little experience driving in weather conditions where there's ice or snow," Scott Weber, INS Acting Director of Investigations, said. "Again, they're motivated purely by profit, they have no regard for the safety of their passengers," Weber said. The van was driving slowly over ice when a tractor-trailer slammed into it from behind. "It started with two injured, and one confirmed dead, and continued to grow as they figured out how many bodies were in the van," Corp. John Lupton, of the Colorado State Patrol, said. There were 20 people in the vehicle, which the INS said was headed from Phoenix to Chicago. Each passenger paid at least $1,000 for the chance to make even more in the United States, the INS estimated. "The stake for them is the future, and the fact that it's $1,000 or $1,500 dollars to get the coyote to get them there is just part of the cost of doing business," immigration lawyer David Simmons said. Simmons said that undocumented workers have fueled our booming economy by taking jobs others don't want. "And under current immigration law, we don't have a valve to let these folks in lawfully. So who do they go to? They go to the smuggler," Simmons said. Previous Stories:

• March 13, 2001: Six Dead After Van Carrying 20 Mexican Nationals Crashes