DENVER (KDVR) -- A Colorado man died on Monday in Hawaiʻi after he became unresponsive shortly following scuba lessons with his family, according to Hawai‘i Island police.

Greg Durocher, 51, of Castle Rock, was participating in the scuba lessons near Hilo, the largest settlement on the big island of Hawaiʻi on Monday when after about 38 minutes in the water he returned to shore "complaining of difficulty breathing."

He then became unresponsive, and that's when Hawai‘i Island police and Hawai‘i Fire Department personnel responded to Waiolena Beach Park just before 12:30 p.m.

The dive master and Durocher’s family started CPR before fire department personnel arrived, and he was taken to a hospital where he died shortly after he got there, police said.

The local coroner will determine the exact cause of death, but police said they are investigating it as a possible drowning. Police do not suspect foul play.