Holland, MI – Investigators are still looking into what caused a large explosion at a townhouse, but confirm the blast originated from inside unit 2.

Holland Charter Township Fire Chief Jim Kohsel told The Sentinel on Thursday afternoon the cause of the explosion is still being investigated, but that it occurred inside the townhouse and was powerful enough to cause structural damage to the building.

“It appears the back (south) wall of the apartment was blown out by the initial explosion,” he said.

Residents of the Pompa Vidals townhouses at 80 E. Lakewood Boulevard said they heard an enormous boom about 11:45 a.m. Wednesday, Nov. 4.

The two people inside unit 2 — two-year-old Layla Cahue-Romero and her grandmother, 60-year-old Maria Gutierrez-Fuentes — were able to escape but were burned in the explosion, said Capt. John Wolffis of the Ottawa County Sheriff’s Office.

Spectrum Health in Grand Rapids listed Gutierrez-Fuentes in critical condition and Layla in serious condition as of Thursday afternoon, Nov. 5.

Kohsel said the water heater in unit 2 was reportedly under some maintenance prior to the explosion and the townhouse complex owner, Ceferino Pompa, said he was called to unit 2 that morning after a resident notified him there was water in the basement, where the water heater is housed.

Pompa said he saw the water heater, which is heated by natural gas, was leaking water and that he shut off both the water and gas to the water heater at approximately 9:45 a.m., about two hours before the explosion.

He said he did not smell any natural gas at that time.

“We’re not sure if that was the source, but there was definitely an explosion,” Kohsel said.

The Ottawa County Sheriff’s Office’s detective bureau is assisting Holland Charter Township Fire Department in investigating the fire. Kohsel said this is the case for every fire in the township and that nothing at this point suggests any criminal activity.

The investigation into the cause and source of the explosion is still underway, he added.

Units 1, 2 and 3 in the seven-unit building were destroyed, and unit 4 had heavy smoke damage. Unit 2 was leveled to the ground. Two vehicles were also destroyed in the blaze.

Sentinel reporter Amy Biolchini contributed to this story.