LOWELL (CBS) - A man was killed during a home invasion on Walker Street, authorities said.

Middlesex District Attorney Marian Ryan and Lowell Acting Police Superintendent Jonathan Webb are calling the man's death a homicide.

No arrests have been made. The man's name was not released pending notification of family.

Emergency personnel responded to Walker Street between Broadway and Waugh Streets early Thursday morning, after receiving a 911 call of a report of an adult male resident of a Walker Street home who had sustained life-threatening injuries.

The male was sent to Lowell General Hospital, where he was pronounced dead.

A preliminary investigation found the man was assaulted during a home invasion, and was later found when a second person, who also lives at the residence, returned home.