ELIZABETH, N.J. — Authorities are trying to determine what started a 4-alarm fire that destroyed three townhouses in Elizabeth.

The Red Cross is helping relocate displaced residents and crews early Wednesday demolished what was left of the structures.

The blaze broke out at about 8:30 p.m. Tuesday at Fairmount and Monroe Avenues.

About a dozen of nearby homes were evacuated as a precaution. Those residents were allowed to return around 1 a.m.

It took firefighters from nine companies about two hours to get the fast-moving fire under control.

Officials say two residents were taken to a hospital for smoke inhalation.