ATLACOMULCO, Mexico, Sept 9, (AP): The freight train’s horn rang out shortly before it cleaved in two a double-decker bus carrying domestic and construction workers to Mexico’s capital on Monday morning, leaving at least 10 dead, more than 50 injured and sending families to hospitals to search for answers.

Minutes earlier Isabel Segundo, 38, was chatting by phone with her 17-year-old daughter Yoana Segundo, who was aboard the bus. Like thousands of others, Yoana is a domestic worker and was commuting to her job as the sun rose over throngs of workers doing the same early Monday. "I was terrified when I saw news of the accident. I thought my daughter had died,” Segundo said.

"We were calling and calling, and all I got was voicemail.” Late Monday, Segundo said she was relieved to hear her daughter survived as she waited outside a hospital with dozens of other families. Medical workers called out names through a megaphone as hospital staff rushed injured people on stretchers into ambulances to be transferred to other hospitals throughout the State of Mexico.

Women cried at the entrance of the medical facility, while others set up a tent in preparation for a long night of waiting to hear of news of their loved ones. Authorities were investigating the accident, but videos of the collision and immediate aftermath showed the bus creeping onto the train tracks as bumper-to-bumper traffic crawled through an industrial area in Atlacomulco, about 80 miles (130 kilometers) northwest of Mexico City.

There was a stop sign and a decrepit railroad crossing sign, but no protective gates or lights to signal an approaching train. Still, even 100 yards away Miguel Sánchez heard the familiar horn blast from the freight train as he started his shift at a nearby gas station. It was the thunderous crash that followed shortly after that surprised him. "We thought it was just a car. We never thought it would be a bus with so many people aboard,” Sánchez said.

Mexico’s train line regulatory authority did not respond to request for comment. The bus line Herradura de Plata said in a statement it was working with authorities and providing "medical, psychological, legal and logistical” help to those affected. The company spokesperson wrote that it "deeply regrets” the accident. The train company Canadian Pacific Kansas City of Mexico in a statement called on drivers "to respect the signage and to comply with the full stop order at railroad crossings, to avoid accidents like the one this morning in Atlacomulco.” The collision left halves of the bus on either side of the tracks.