BOSTON (WHDH) -- A 9-month-old was rescued after he was locked inside an SUV while the boy’s mother was grocery shopping Sunday.

The baby’s mother said she forgot that she had brought the baby to the store.

“Another shopper got out of their vehicle and notice a child in the back of the car,” said Matthew Bergin, senior property manager of the Charles River Plaza.

Authorities say the mother parked her car in the Charles River Plaza parking lot and went grocery shopping. It was just before 1 p.m. and the temperature was in the 90s.

An alert shopper and a security guard rescued the baby.

“[The security guard] was just returning from doing a security tour at another property,” Bergin said.

Police say the mother left her 9-month-old in the car for about 30 minutes. They say once she realized what she had done, she came running out of the Whole Foods, only to find police and a crowd standing around her vehicle.

“As the security guard, he needs to see what the crowd is. Is it a medical emergency? Is it a vehicle emergency? The motorists, the passersby, everyone was concerned. And then the security guard took his appropriate actions. A very happy ending,” Bergin said.

Police said the child was alert and was taken to Mass. General Hospital.

No charges have been filed but the Department of Children and Families is investigating.