WOBURN — A 3-year-old who went missing in Woburn Tuesday afternoon was found unresponsive in a swimming pool and was later pronounced dead at Lahey Hospital in Burlington. The boy was pronounced dead around 9 p.m. Tuesday night, the Middlsex District Attorney's office said in a statement, and the investigation into his death was ongoing.

"The preliminary investigation suggests the child had been submerged in an in-ground pool for an extended period of time," the office said in a statement. No foul play is suspected and no additional information was being released at this time. The office is charged with investigating unattended deaths.

Woburn Police responded to a call of a missing child at 59 Marlboro Road in Woburn at 4:47 p.m. and were told by family members the boy had last been seen at 3:30 p.m. Neighbors began posting information about the boy on social media, describing him as an African-American boy with autism who was wearing a white, long-sleeved t-shirt and black shorts when he went missing.