The boys' family called for help Sunday after the boys went missing on the water on the west side of Pleasure Pier around 4:30 p.m.

The brothers, identified as Josue and Jefferson Perez according to KHOU-TV, were last seen in chest-deep or waist-deep water, officials said. No one confirmed seeing the boys who do not know how to swim go underwater. 

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"So essentially what happened is they were out in the water, the parents briefly lost sight of them, and they looked back up into that area, and they did not see them any longer," Lt. Austin Kirwin with Galveston Beach Patrol told FOX 26. 

The search continues for the other missing teen.

Multiple agencies including the Galveston County Community Emergency Response Team, Beach Patrol, the U.S. Coast Guard and volunteers have participated in the search efforts.