>Galveston was a tricky area for all levels of swimmers. On the Gulf side of the island the water is treacherous. There are sandbars and places where the ocean floor drops away unexpectedly. The riptides are a constant issue, pulling under experienced and inexperienced swimmers alike.
>
>The peril was increased because in the early 1900s, few people learned water safety. The first swimming programs in the U.S. began in 1912 (see Wilbert E. Longfellow), and the programs were slow to spread throughout the country. Those who came to Galveston for vacation often did not know how to swim, because few towns and cities had public access to pools.
>
>Yet summers were hot, and there was no air conditioning until the late 1920s-1930s. Many traveled to Galveston to enjoy the cooling ocean breezes, and of course, they went into the water.
>
>Take unpredictable currents and mix in crowds of people who don’t know how to swim (or how to swim well), and Galveston had the makings of daily disaster.
>
>...
>
>Colombo’s additional advantage was that he grew up near the Galveston waters. He had intimate knowledge of how the ocean could behave in all types of weather.
>
>...
>
>Colombo often had to rescue the original victim as well as those who were trying to help.
>
>...
>
>During World War II, the beaches were overrun by soldiers on leave before shipping out, and the crowds were overwhelming. On one single afternoon, he saved 19 people.
>
>One of Colombo’s most dramatic rescues was when a tugboat hit a barge, and the barge burst into flames that quickly engulfed the tugboat. To rescue those on board, Colombo dove under the flames several times to save the men.

Tldr; it was a dangerous area and people apparently used to drown a lot!