STAMFORD — A college student who was pulled from the YMCA’s pool last week remains in critical condition as police continue to investigate the incident.

Investigator Mike Longo said the 22-year-old University of Connecticut-Stamford student has been transferred to Columbia Presbyterian Hospital in New York where he is still unconscious.

Police have not released the name of the student, who is from China, because they are not sure his family has been notified.

The student was pulled from the Stamford YMCA’s pool about 4 p.m. Friday after a friend he was swimming with noticed he was underwater.

Unlike the near drowning of a 5-year-old New Canaan boy at Chelsea Piers in August, there were no video cameras near the YMCA pool to record the incident last week.

Police said video at Chelsea Piers revealed the boy was underwater for more than four minutes before the lifeguard noticed. The child has recovered, while the 23-year-old lifeguard has been charged with reckless endangerment and risk of injury to a minor.

Longo said it’s unknown how long the UConn student was underwater.

“At this time, we are trying to get a timeline, but nothing is concrete,” he said. “The time he was underwater varies from a couple of different witnesses. Right now, it depends upon when they took note of what was going on.”

Longo said police plan to speak to more witnesses.

“The safety and well-being of everyone who enters our facilities is the Y’s top priority,” according to a statement released by Stamford YMCA Executive Director Clinton Hamilton.

“Our staff responded as they were trained to do and we are hopeful for a positive outcome. The thoughts and prayers of everyone at the Stamford Family YMCA are with the man’s family and friends.”