A massive manhunt is underway for a suspect in a shooting at an East Garden City business that left one person dead and another in critical condition.

Police say Sang Ho Kim walked into 645 South St. and shot the store owner and an employee at around 10:10 a.m. Police say Kim is a disgruntled former vendor to Savenergy, the company located at the address.

An unidentified store employee died in the shooting. The man listed as president of Savenergy, John Hyung Choi, is in critical condition in the ICU at Nassau University Medical Center.

Police say Kim is between 6 feet and 6 feet 3 inches tall and was seen wearing either a brown or gray suit jacket. Kim was last seen fleeing the area toward the Roosevelt Field Mall, possibly driving a Honda Pilot with registration FMA 3648.

A lockout at Garden City School District schools and a lockdown at Nassau Community College were put into effect after the shootings, but have been lifted. The lockout at Roosevelt Field Mall has been lifted.

Police say they are asking the public for help in locating Kim and believe he is armed and dangerous.

A law enforcement source has confirmed possible sightings of Kim in Orange County.

Police have assured the public that they do not believe this is a shooting rampage.

For extended footage on the shooting, watch the clips to the left or click News 12 Extra on Optimum TV channel 612.