Hundreds showed up at local Sikh temples in Wheaton and Palatine. Candlelight ceremonies were held for those who lost their lives and for their families.
"Our community is shocked. We've never handled something like this before, so this is a big challenge for us," said Ravi Singh, Illinois Sikh Community Center spokesperson.
The faithful flocked to gurdwaras, or Sikh houses of worship, in west suburban Wheaton, in Palatine, and on Chicago's North Side during the day Monday.
Several who worship locally were familiar with the six people killed.
"We're not the other; we're your brothers and sisters; we live down the street; we're the doctor; we're the engineer; we're the cab driver; we're the gas station guy; we're your neighbors," said Shiva Singh Khalsa, President & Chief Executive Officer of the Spirit Rising Foundation.
Sikhism is a monotheistic faith founded more than 500 years ago in south Asia.
There are about a half a million followers of Sikhism in the U.S., and because observant Sikhs wear turbans and beards, they are often mistaken for Muslims or Arabs and have sometimes become targets of religious intolerance after the attacks on September, 11, 2001. Sikhism is a faith that was founded about 500 years ago in South Asia.
Organizers an inter-faith gathering Monday night will promote healing amid the expressions of anger and sorrow.
"Today is the first step in the right direction, but I think it's going to take a period of time, and I think we also have to wake up as a greater Sikh community that we have do a better job of educating everyone on who we are," said Ravi Singh.
Temple officials in Wheaton say their members are setting up a fund for people who were killed and families of those who were critically injured, including a police officer. The Wheaton vigil starts at 6:30 p.m. Monday night.