MERRIMACK — Police say they are investigating the circumstances that led to the death of a dog last weekend at Wasserman Park.

“We are aware of the incident and we are actively investigating. We have identified everyone involved,” said Deputy Chief Brian Levesque of the Merrimack Police Department.

According to Levesque, the fire department received a phone call around 7:30 p.m. on June 8 for a dog rescue at the park on Naticook Road. The dog, an 11-year-old golden retriever named Bailey, ultimately drowned.

Although police would not release specific details of the situation that took place at the park, in an effort not to impede the investigation, Levesque said authorities are speaking with everyone involved in the incident.

Hannah Riedy and Mark DiPirro, who graduated last Saturday from Merrimack High School, were at the park at the time and tried to administer CPR to the dog.

The couple called the fire department to report the incident.

The dog’s owner, a woman, was at the park with Bailey and another dog, according to an online post from Riedy. Riedy said the woman and the dog were on the dock when the woman allegedly “pushed (Bailey) into the water and he went straight under. He came up and started gagging and choking on water.”

Riedy said she asked the woman if she wanted her to help, but the woman replied that the dog was fine. According to Riedy’s post, the dog was struggling to swim and went under after two minutes.

“I began to swim faster, Mark jumped in and we both somehow managed to lift the 150-pound dog onto the docks as the woman watched. She wasn’t crying or yelling for help — she just stood there watching,” said Riedy.

After attempting CPR for about 10 minutes, the dog died, she said, adding the woman did nothing to help, but was allegedly on her phone talking to her daughter, “laughing — not really concerned as her dead dog was laying on the dock in our arms.”

“ … Overall, we don’t want any harm to come to this woman … we don’t believe her intent was to kill Bailey,” said Riedy, who expressed concerns about whether the woman was capable of caring for her other, smaller dog.

Riedy did not respond to an inquiry for further comment.

If the police department decides to bring forward any criminal charges in the matter, Levesque said a press release will be issued.