The leading engineer in Spain's search, now on its fourth day, for a 2-year-old boy trapped in a deep, narrow borehole says rescuers are rushing to finish in days massive digging work that usually takes months.

Efforts to rescue Julen Rosello from the 110-meter (360-foot) deep, 25 centimeter-diameter (10-inch) borehole have gripped Spain since the boy reportedly fell into the waterhole on Sunday.

Adults don't fit through the shaft and machinery has hit an obstruction of strong material about two thirds down the vertical hole.

Emergency services look for a 2 year old boy who fell into a well, in a mountainous area near the town of Totalan in Malaga, Spain, Monday, Jan. 14, 2019. More than 100 firefighters and emergency workers in southern Spain are searching for a 2-year-old toddler who fell into a narrow and deep well on Sunday. Rescuers believe the boy fell into the 100-meter-deep well after walking away from his parents. (AP PhotoGregorio Marrero)

Emergency services look for a 2 year old boy who fell into a well, in a mountainous area near the town of Totalan in Malaga, Spain, Monday, Jan. 14, 2019. More than 100 firefighters and emergency workers in southern Spain are searching for a 2-year-old toddler who fell into a narrow and deep well on Sunday. Rescuers believe the boy fell into the 100-meter-deep well after walking away from his parents. (AP PhotoGregorio Marrero)

Angel Garcia of the Malaga province civil engineers' association told reporters on Thursday that workers' priority is now to dig two parallel vertical tunnels. That plan came up after a horizontal hole bored in the past 24 hours from a hillside hit heavy stone.

Emergency team members look for a boy fell into the 100-meter-deep waterhole in a mountainous area near the town of Totalan in Malaga, Spain, Monday, Jan. 14, 2019. More than 100 firefighters and emergency workers in southern Spain are searching for a 2-year-old toddler who fell into a narrow and deep well on Sunday. Rescuers believe the boy fell into the 100-meter-deep well after walking away from his parents. (AP PhotoGregorio Marrero)

Emergency team members look for a boy fell into the 100-meter-deep waterhole in a mountainous area near the town of Totalan in Malaga, Spain, Monday, Jan. 14, 2019. More than 100 firefighters and emergency workers in southern Spain are searching for a 2-year-old toddler who fell into a narrow and deep well on Sunday. Rescuers believe the boy fell into the 100-meter-deep well after walking away from his parents. (AP PhotoGregorio Marrero)