Second Twin Baby Dies Days After Sister Found Dead In Bed

A six-week-old baby has died in hospital, days after her twin died at her parents' Brisbane home.

Police and paramedics were called to the home at Sunnybank Hills on Wednesday where one of the six-week-old pair was confirmed dead.

Her twin was transported to hospital in a critical condition, but police say she died on Thursday.

"Sadly, a six-week-old baby girl who was transported to hospital on November 27, passed away yesterday," QLD Police announced on Friday morning.

Their deaths are not being treated as suspicious.

"Preliminary investigations suggest the babies were sleeping together throughout the night and were discovered unresponsive in the morning," police said in a statement.

An unnamed neighbour said she was woken by an ambulance and she heard the father "howling" for hours afterwards.

"He was howling and screaming," she told The Courier-Mail.

"I thought someone was dead and it really scared me. He was so upset."

A report will be prepared for the coroner.