On Adrienne Kromer's first day back at work following three and a half months of maternity leave, she called her daughter's new daycare center three times to check on the baby girl.

McKenna Felmly had shown no signs of illness or distress when she was dropped off at the Lehigh Township, Pa., center in the morning, her dad, Bryan Felmly, writes on GoFundMe.

But Kromer was nervous, and when the daycare center told her McKenna was having trouble taking a bottle, and later said she'd fallen asleep quickly (a rarity for the infant), Kromer decided to leave work early and pick up her daughter.

Just minutes after she left, the daycare center called her and told her McKenna wasn't breathing. By the time Kromer arrived, McKenna had been transported to the hospital; soon after Kromer and Felmly arrived at the hospital, doctors told them they couldn't save the couple's little girl.

Per the Allentown Morning Call, daycare workers found McKenna unresponsive in her crib and attempts to revive her began at the daycare, but she was pronounced dead upon her arrival at the hospital.

An autopsy showed no signs of trauma and police say the death does not appear suspicious at this time, but a cause of death won't be determined until toxicology and viral tests are completed and other aspects of the case, including the crib, are investigated.

"We are continuing to conduct interviews with family, friends, and employees of the daycare," the police chief told Lehigh Valley Live Wednesday. "We still have some work to finish yet. I can't say when we will determine manner of death." The Times News says it could take as long as three months.

The daycare center has a valid certificate of operation and had last been inspected in January. (Last year, a New York 3-month-old also died on his mom's first day back at work.)

This article originally appeared on Newser: Baby Dies on First Day at Daycare

More From Newser