U.S. President Donald Trump is heading to central Texas on Friday to survey damage from the July 4 flash flood that killed at least 120 people and left dozens more missing.

The alert, a Blue Alert issued by the FBI, named Benjamin Song, 32, as the suspect wanted in the July 4 shooting of a police officer at the Prairieland Detention Center in Alvarad

Over just two hours, the Guadalupe River at Comfort, Texas, rose from hip-height to three stories tall, sending water weighing as much as the Empire State building downstream roughly every minute it remained at its crest. The force of floodwater is often more powerful and surprising than people imagine.

Search crews slogged through thick mud and debris Tuesday in central Texas, where more than 100 people are confirmed dead after catastrophic flooding.