Investigators said Jessy Paola Moreno Cruz, 32, was facing severe financial problems and recently was kicked out of her home.
With no resources to rent a new place, she and her son became homeless for a while.
She then spiraled into a deep depression. So, feeling like she had no one to turn to, she made the fatal decision to end her life, taking her child with her.
A video of the scene captured the fateful moment the distressed mother decided to jump from the bridge while holding her son. Meanwhile, onlookers and emergency responders tried begging her not to end her and her son's lives.
However, she ignored their pleas and plunged 100 meters (330 feet) down the bridge, killing them both.
In the distressing clip, an emergency responder shouted in disbelief.
"Oh my God... she threw herself off!"
Following the incident, firefighter Rafel Rico said in a statement to local media:
"They begged her not to do it and tried to convince her to stop... but sadly, she took the fatal decision."
The shocking incident took place on the La Variante Bridge in the Ibague community in Tolima's central-western Colombian area.
Investigators said Jessy left behind a suicide note that elaborates on the events that led up to her decision.
"I cannot tolerate the idea that somebody could hurt you because of what I did; I prefer that we leave and forget this world.
I have no hope; I have been defeated and humiliated.
The man who told me he loved me left me alone, very alone.
They all left me with nothing. They snatched away in an instant everything I worked for, everything I lived for, all I loved, all I gave.
My mistake was to trust the wrong people. I failed the person I love most in my life; I cannot afford to pay for his studies, I do not even have enough money to give him hot food.
I have placed him in danger, and I am sorry for failing you, son."
The note continued:
"Every day is more difficult and filled with threats, debt, and lack of love. I cannot do it anymore.
I will be told I am a coward, but only God knows the distress of being terrified that someone will hurt you because of me.
If only somebody could help me, but who can lend me the money or even a home? There is nobody.
The world is dangerous, and I cannot protect you. Every day is grey. My heart beats with anxiety. I cry with frustration and impotence. I am a loser.
This time, I will not fail you, my son. Nobody will hurt us anymore."