CRESSON, Texas – Amber Gutierrez repeatedly dialed the cellphone number of her boyfriend on Friday, hoping that the man missing after a Texas chemical plant exploded would answer or rescuers would hear the sound and find him.Dylan Mitchell’s phone still rings a day after the blasts, giving her hope that he is alive, but she hasn’t heard from authorities searching the plant.Resting her elbows on a ranch gate near the site of explosions at a Tri-Chem Industries plant in Cresson, 50 miles (80 kilometres) southwest of Dallas, Gutierrez waited Friday afternoon for news along with Mitchell’s brother and cousin.Gutierrez said Mitchell moved with the company from their Arlington warehouse when they opened the plant about a year ago in Cresson.“He did everything around here,” she said, gazing at the partially collapsed chemical plant. “He gave his life to this place — literally.”Two other workers were injured in the explosion. One was released from the hospital after being treated for chemical contamination while the other remained in serious condition with severe burns from the waist up.Tri-Chem’s Cresson plant stored chemicals that were toxic, flammable and corrosive, according to Hood County records of the company’s 2017 Tier 2 chemical inventory. The county did not have company emergency response plans in its files.The intermingling of chemicals spilled from ruptured drums, the still-smouldering fire and a rush of outside air coming in as heavy equipment removed the 15,000-square-foot (1,400-square-meter) building’s collapsed metal beams all threatened to trigger another boom.“It’s a land mine,” Hood County Fire Marshal Ray Wilson said Friday.The search for Mitchell proceeded slowly Thursday evening and all day Friday while hazardous material and firefighter crews took turns evaluating risks. Work was halted when night fell on the scene and would continue Saturday, Wilson said.Wilson said the plant contained acids that react to heat, pressure and water, which is why they haven’t yet turned on the fire hose.Texas Department of Public Safety Staff Sgt. Earl Gillum said experts determined there were no air quality issues Thursday, but that the site remains dangerous because of the chemicals still to be cleaned up.There is a fertilizer plant adjacent to the Tri-Chem plant, but Wilson said there was “no known threat” to that facility.Investigators believe a worker dragging his foot along the floor while chemicals were being mixed sparked Thursday’s explosion.A medical helicopter landed Thursday at MotorSport Ranch, a private race track several miles from the plant, but the worker was too injured to fly, according to the ranch’s director of safety and volunteer Cresson firefighter, David Piontkowski.He said the man was upright and speaking, though so badly burned that medics had to drill into his shoulder bone to deliver morphine to keep him from going into shock.The worker was taken by ambulance to Parkland Memorial Hospital in Dallas.Jessica Gregg told television station KXAS that the man taken to Parkland was 27-year-old Jason Speegle, her son-in-law. Catherine Bradley, a spokeswoman at Parkland, said Speegle was in serious condition Friday.Another worker was treated for less severe injuries and released from a hospital in Granbury on Friday.Wilson said a deputy fire marshal was hospitalized Thursday with breathing difficulties, but was treated and released.___Associated Press writer Jamie Stengle contributed to this report from Dallas.