LEWISTON — State and local police on Tuesday were investigating the death of a baby found in a bathtub Monday afternoon in a Lewiston apartment.

Police said Sean St. Amand, 27, placed the boy, who would have turned 1 on Oct. 30, in the tub with his 2-year-old sister for a bath. St. Amand is the father of both children. When he later checked on the children, the boy was unresponsive.

An ambulance was called, and the baby was declared dead on arrival at Central Maine Medical Center.

The boy shared his father’s name,

.

Police said the incident took place at 125 Pierce St. The boy’s mother, Jennifer Everett, 28, was taking a nap in the apartment at the time.

Police did not know why the father left the room or how long he was gone.

“That’s all something we’re trying to pinpoint,” Maine Department of Public Safety spokesman Stephen McCausland said.

Tuesday morning, a pair of baby strollers sat abandoned in the grass outside the apartment building. Dan Relph, the couple’s upstairs neighbor, sat on the front porch as he waited with a young child for the school bus.

Relph said he heard about the baby’s death Monday afternoon when he came home from doing laundry. Police arrived first, then crime scene investigators.

“They kind of monitored the traffic coming in and out of the building,” Relph said.

He said investigators stayed until about 8 p.m.

Relph said he didn’t know St. Amand or Everett well, but “they seemed like a typical couple.”

The building’s landlord said the family was gone Tuesday. He declined further comment.

Police had interviewed the parents and would interview other family members and friends, McCausland said. Police also were awaiting autopsy findings from the Medical Examiner’s Office.

A representative for the Medical Examiner’s Office said results were not expected to be released Tuesday.

McCausland said the Maine Department of Health and Human Services typically is notified when a child dies and other children remain in the family, but he did not know whether the department was involved in this case.

A memorial fund has been set up at GiveForward.com to pay for the baby’s funeral expenses. Meghan Avery is managing the page. Her relationship to the couple was unclear.

On the fundraising page, she called baby Sean “a very handsome little boy with the most beautiful eyes. He was a complete distraction to anyone that he was around, with his bubbly personality and contagious smile.” She said he died “in an unexpected and horrific accident.”

ltice@sunjournal.com