Among those killed in the mass shooting at a Fourth of July parade in the Chicago suburb of Highland Park were a teacher at a synagogue and a man in his 70s who came from Mexico to visit his family.

Nicolas Toledo was the first victim identified as of late Monday by his family after a gunman on a rooftop opened fire on families at the parade on Monday, killing six and wounding more than 36.

"My grandfather Nicolas Toledo father of eight and grandfather to many left us this morning July 4th, what was supposed to be a fun family day turned into a horrific nightmare for us all," his granddaughter, Xochil Toledo, said.

"Not only was Nicolas a loving man, creative, adventurous and funny. As a family we are broken, and numb," she said.

Toledo's family set up a page on crowd funding service GoFundMe to raise money to send his body back to his native Mexico. The page raised more than $33,000, as of early Tuesday.

Toledo, in his 70s, had been visiting his family for about the past month. He spent his final days swimming and fishing and being among relatives, his family told media.

Relatives of Toledo were wounded in the shooting but were expected to survive, CBS Chicago reported.

Another person killed in the shooting was Jacki Sundheim, a teacher at a Highland Park synagogue. The North Shore Congregation Israel confirmed her death in an email to congregants.

"There are no words sufficient to express the depth of our grief for Jacki's death and sympathy for her family and loved ones," the synagogue said.

"Jacki's work, kindness and warmth touched us all, from her teaching at the Gates of Learning Preschool to guiding innumerable among us through life's moments of joy and sorrow, all of this with tireless dedication," it added.

The synagogue said she was survived by her husband and daughter.