She had little reason to be suspicious -- the quiet Spanish beach village where she has lived for almost 20 years is filled with holiday houses. People come and go all the time.
But on Wednesday night a deafening bang rocked Gil, 50, from her sleep. She ran outside to see smoke billowing from what remained of the property down the road.
The powerful explosion had leveled the one-story house in the Montecarlo neighborhood of Alcanar, leaving one person dead and another seriously injured.
Center of investigation
The house in Alcanar
is now at the center of a wide-ranging investigation into a previously unknown terror cell
believed to be behind last week's attacks in the Catalan capital and in the coastal town of Cambrils.
Police suspect the property was being used as a base to make explosives that could have caused even greater devastation
, had they not blown up in what investigators believe was a premature explosion.
A secondary uncontrolled blast on Thursday afternoon blew out a window in Gil's house and left rocks strewn across her yard.
Standing on her front porch, tape from a police cordon fluttering nearby in the wind, Gil says she was shocked to learn that the suspects had been hiding in plain sight just meters away.
"It was a surprise and we were very scared," says Gil. "It's a good community, very tranquil, we never thought we would have terrorists here."
She is exhausted following days of controlled explosions in the neighborhood, conducted by authorities as part of their investigation.
"I feel very tired, it's a feeling of being powerless ... angry," Gil says, tears welling up in her eyes. "This is the first time something of this magnitude has happened and I hope it's the last."
The ideal location
The municipality of Alcanar, 120 miles southwest along the coast from Barcelona, is made up of a string of sleepy beach towns, home to around 9,000 people -- a mix of year-long residents and others who spend the occasional weekend here.
The tourists who pass through each summer are drawn to a sandy coastline dotted with orange groves and olive trees.
For the suspects believed to be part of the terror cell, it offered an ideal location to plot their attacks away from prying eyes.
Alcanar's vice-mayor, Jordi Bort, told CNN that the house the men were squatting in was owned by a bank, which did not know that people were residing there illegally. The house's septic tank was used as storage for the explosives, Bort said.
A source briefed on the investigation
said a preliminary assessment indicated there were traces of the powerful explosive TATP
in the rubble. Used in recent terror attacks across Europe, including those in Brussels and Manchester, TATP can easily result in accidental detonation if mistakes are made during its preparation.
Police said Friday there were other "biological remains" found at the site, but it is unclear whether they belong to someone other than the one person confirmed dead.
The roof of the nearby Hostal Montecarlo overlooks homes that were damaged in the explosion, their facades pockmarked and windows blown out. Bikers buzz past the scene of the investigation on the coastal road as armed police patrol the area. On the other side of the hotel, facing the sea, a pool sits idle.
Inside the hotel, Cristina Bolz is standing behind the bar making espressos for a handful of journalists and tourists.
Bolz, who has been working at Hostal Montecarlo for nearly 40 years, says that local residents frequent the hotel for drinks, mingling with tourists.
A few people sit at tables in the hotel's restaurant, watching the news, which is broadcasting the latest updates on the investigation.
"It's a small town, quiet, relaxing," Bolz says, in between taking orders. "People are very nice."
It's precisely the type of atmosphere that the Schenks -- tourists from Stuttgart, Germany -- were seeking when they booked a three-week holiday in Alcanar.
Unknown to them, the Schenks' rental was just a few doors down from the suspects' property. They were sitting in their living room on Wednesday night when the blast rattled their rental home.
"We saw two big fire balls and heard a loud boom," Juliane Schenk, 17, says.
"It's been an adventure holiday," her mother Sabine adds with a cautious laugh.
Less than a mile down the road, retirees sunbathe and children play soccer on Playa Cementera, a beach that lies in the shadow of an imposing cement factory. When the explosion went off four days ago, many people here immediately assumed the factory was the source.
Josep Romera, 30, and Elena Gonzalez, 36, are playing in the surf with their four-year-old son.
They came to Alcanar for a getaway.
"This is a quiet area, more quiet than the area where we live in Girona, the beaches are very touristic there," Romera says.
In the wake of the blast, Romera says that Alcanar's annual eight-day Festa Major has been canceled. The local festival, popular among tourists and which boasts its own running of the bulls, was shutdown as a precaution following the spate of attacks.
"It is very sad what happened in Barcelona and what happened here, and it is very scary," Romera says. "There is fear... a lot of fear... it can happen here, there... you never know."