SAN DIMAS ( — The owner of a Quiznos restaurant in San Dimas is in critical condition after he was shot during a robbery Tuesday, authorities said.

Los Angeles County Sheriff’s Department deputies responded to a call of an assault with a deadly weapon at the chain restaurant in the 1000 block of West Arrow Highway shortly after 3 p.m.

READ MORE: NFL Announces All-Pro Rosters; Kupp, Donald, Ramsey Make First-Team

Arriving deputies found a man suffering from a single gunshot wound to the torso area.

The victim, a 63-year-old San Dimas resident and the restaurant’s owner, was airlifted to a hospital.

Witnesses told deputies an unknown male suspect had entered the business, approached the cashier’s counter, brandished a semiautomatic handgun and demanded money from the victim.

The business owner handed the suspect a bag containing U.S. currency, according to deputies.

READ MORE: 'Our Hearts Are Heavy:' Sandra Shells, ER Nurse Attacked Near Union Station, Dies From Injuries On Sunday

Investigators say the victim then followed and confronted the suspect outside the business. The victim and suspect were involved in a brief struggle, during which the suspect shot the victim before fleeing on foot in a southwest direction, according to deputies.

Sheriff’s Department Sgt. Rebecca Rodriguez said an investigation is continuing. However, she warns victims not to confront suspects in similar situations.

“You just want to be cooperative. If somebody has a gun, just give them your money. And then we will investigate later. We don’t want anyone to get hurt,” Rodriguez said.

The suspect was described as a male, white or Hispanic, age 25-30, approximately 6 feet tall and 175 pounds. His clothing was described as a black cap, black shirt and dark shorts with a plaid pattern.

MORE NEWS: Sheriff's Deputies Searching For Missing Rosemead Man

Anyone with information about the crime or the suspect is asked to call the department’s San Dimas station.