2 killed after tree branch falls during fireworks show in Rock Island, Ill.

ROCK ISLAND, Ill. (WLS) -- Two people were killed and five others injured after a tree branch collapsed on them during a fireworks event in Rock Island, Ill.

It happened suddenly Tuesday night at a celebration while dozens of people were sitting under a tree near the Rock Island County Courthouse. The Red, White and Boom fireworks show had started minutes before.

The Rock Island Sheriff's Department said the branch fell without any warning, crushing families sitting underneath the tree.

Many got away safely and others tried to lift up the giant branch to help those trapped beneath it.

The tree branch fell about 25 feet to the ground from a 100-year-old oak tree. Some spectators who heard the sudden collapse thought it was part of the fireworks display.

The branch had a circumference of just over eight feet at the base and was 45 feet long.

The sheriff said Daniel Mendoza Sr., 61, of Rock Island was pronounced dead at the scene and Lawrence Anderson, 72, of Moline, was transported to a hospital, where he was later pronounced dead.

A pregnant 21-year-old woman was among the injured. She was transported to a hospital and gave birth to a baby. Both are in good health.

Four other people were taken to hospitals and were treated and released.

Investigators are looking into the cause of the incident, but said that weather does not seem to be a factor.