It's happened before. It will likely happen again, sadly.

A 26-year-old man -- said to be from Minnesota -- was walking along the Chicago Riverwalk on Sunday night when he dropped his cell phone into the icy water.

As CBS Chicago reports, he clambered over the railing in order to get it back.

Instead, he fell into the water and got into trouble.

Two friends, a 23-year-old man and a 21-year-old woman, jumped in after him.

Divers were called. They managed to get the two men out of the water, but the woman is missing, presumed drowned.

The man who had dropped the cell phone died in the hospital. The friend who jumped in to save him is said to be in critical condition.
Very sad, one person dead, another missing(likely dead), and a third in critical condition.

This has happened before though. Another part to the story.

Last year, a man was killed by an oncoming train in the Bronx after jumping onto the subway tracks to search for his dropped cell phone.
In another case, again in New York, a man was electrocuted after jumping onto the tracks.
The whole story here: Man dies after jumping into icy river to retrieve cell phone | Technically Incorrect - CNET News