At approximately 11:24 a.m., of the Port Isabel Station was performing sensor response patrol duties alone in a Service vehicle, traveling on Alton Gloor Road in Brownsville, Texas. An eyewitness stated that Agent Maldonado's vehicle turned left across the center line of the road, sliding across the roadway and into the ditch adjacent to the road. It then struck an earthen berm with its passenger side tires and rolled over one complete turn, landing on its wheels. At the time of the accident, Agent Maldonado was driving in an emergency response mode with his vehicle's emergency lights and siren activated.
Supervisory Border Patrol Agent Herbert J. Monette of the Brownsville Station was notified of the accident and arrived at the scene soon afterward, as EMS personnel were trying to save Agent Maldonado. They then decided to transport Agent Maldonado to Brownsville Medical Center, where emergency room personnel also tried to save him, but about 12:15 p.m., Agent Monette was informed that Agent Maldonado had died from wounds sustained in the accident. The likely cause of the accident was the wet condition of the roadway.
Agent Maldonado began his Border Patrol career with the Laredo Sector. He was promoted in August 1988 to Senior Patrol Agent at the Port Isabel Station in the McAllen Sector, the position he held at the time of his death.