Father's horror as he finds BOTH of his four-year-old twin sons dead in pool in their grandmother's backyard

Police are investigating the deaths of twin four-year-old boys who drowned on Tuesday night in their grandmother's backyard swimming pool.

Luke and Mark Nguyen, of Grand Prairie, Texas, were unresponsive but still alive by the time police arrived at the home shortly after 10.30pm.

They were pronounced dead on arrival at the Medical Center of Arlington.

Scroll down for video

twin1.jpg
twin2.jpg

Tragedy: Twins Luke and Mark Nguyen were found floating in a relative's swimming pool and were pronounced dead in hospital

Scene: The twin boys were found dead in the swimming pool of the backyard of this Grand Prairie residence

Scene: The twin boys were found dead in the swimming pool of the backyard of this Grand Prairie residence

Area: A drowning call went out to Arlington firefighters and police at about 10:30pm on Tuesday in the 3200 block of Hunter Cove Drive in Arlington

Area: A drowning call went out to Arlington firefighters and police at about 10:30pm on Tuesday in the 3200 block of Hunter Cove Drive in Arlington

It is believed the father - who has not been named - found his twin sons floating in the water and pulled them out to try and save them.

Authorities believe the boys slipped in unnoticed through a gate around ten minutes after arriving at the home.

Their mother Huong Nguyen spoke to News 8 about her tragic loss, sobbing while she called the boys her 'blessings'.

She said her husband went to check on the boys' grandmother as she has diabetes. It is believed this is when the boys slipped out to the yard

Arlington Police Department spokesperson Tiara Richard told CBS: 'Early details are that this looks like an accidental drowning involving two young boys.'

Police detectives have spoken with the family and believe the drownings were accidental and that no negligence was involved. The family faces no charges.

Autopsies are scheduled for later this week.

The comments below have been moderated in advance.

The views expressed in the contents above are those of our users and do not necessarily reflect the views of MailOnline.

We are no longer accepting comments on this article.