CHICAGO (CBS) — Thursday marks the 28th birthday for a pregnant Chicago postal worker who disappeared nearly two years ago.

“I’m knocking on doors. I’m kicking in doors. I’m climbing abandoned buildings. I’m digging in garbage cans,” said Kierra’s father, Joseph Coles.

Family and friends of Kierra Coles held a celebration Thursday, saying they are not giving up hope of finding her.

Coles, then 26, was last seen Oct. 2, 2018 at 81st Street and Vernon Avenue in the Chatham neighborhood, and was three months pregnant at the time.

Kierra Coles was last seen on Oct. 2, 2018, near 81st and Vernon. (Credit: Chicago Police)

The case has left her family – and Chicago Police detectives – stumped.

Coles had called in sick to work the day she disappeared. But surveillance video showed her wearing her U.S. Postal Service uniform, walking up and down the street the morning she vanished.

Her family has said they found her car parked on her block, with her cell phone and purse still inside.

Joseph Coles says he believes Kierra and her baby are alive.

Coles’ family and the U.S. Postal Service have offered more than $46,000 in reward money for information leading to her whereabouts.

Anyone with information on Coles’ whereabouts should call Area Two detectives at (312) 747-8274.