A second infant has died following a single car crash in Troy Township on Tuesday.
Police say that their mother was speeding when she hit a set of railroad tracks and lost control.
Six-week-old Presley Massingil died in the crash and her twin brother, Parker, died Thursday night.
After the accident, authorities reported that neither child was properly strapped into their car seats.
Officials said the twins' seats were too large for the infants.
Their mother Lori Massingil of Ida, Michigan was not seriously injured.