A man aboard a Frontier Airlines flight en route to Houston had to be restrained by fellow passengers on Wednesday after he began kicking seats and hitting a window, eventually breaking the interior Plexiglas cover, police said.

       The flight, F9 4856, departed from Denver and was in the air for about 20 to 30 minutes, when a woman asked the man behind her to switch seats, according to passenger Victoria Clark. This man quickly became enraged, profusely kicking the woman’s seat and trying to break the window, Clark said.

       "I started having a panic attack," Clark told ABC News. "[I thought] it could be a terrorist attack."

       The man continued to hit the window and was eventually able to crack it, passengers said. Without an air marshal on board, flight attendants asked if there was any law enforcement to help, passengers recounted. That’s when Tanner Phillips, a former member of the military, said he stepped in.

       "This guy was just going crazy," Phillips told ABC News. "He was screaming in multiple languages, punching out the window and laying back and trying to kick it out. I wanted to help as much as I could."

       Phillips said he and several others grabbed hold of the man, using zip ties and boot laces to restrain him and put him back in his seat. Instead of making an emergency landing, the flight continued toward its destination of Houston — forcing the group of good Samaritans to ensure the man did not escape for about two hours.

       The man's blood was everywhere around the window and the ceiling of the aircraft, since the Plexiglas cut up his hands, Phillips said.

       "You never know what someone is capable of," Phillips said. "I’m really grateful that we were able to handle the situation and no one got harmed."

       Once the plane landed safely in Houston at around 10:20 p.m. local time, Clark said everyone felt an immense sigh of relief.

       "People were clapping," Clark said. "Everyone was saying thank you to all the gentlemen that helped make sure that we got there safely."

       The Houston Police Department said they received a report that there had been a "combative passenger on board," and were already on the scene by the time the plane had landed.

       Frontier Airlines declined to press charges at the scene, and police are reaching out to airport officials to see what happened to the man. Since the man is not currently facing charges, his name was not released, according to police.

       Several passengers, including Jessica Brown and her daughter Chloe Starks, hope this incident shows the need for increased security aboard aircrafts, so that something like this does not happen again.

       "It’s just insanity. I don’t wish this on my worst enemy," Brown told ABC News. "I wish in 2025 we would not have situations like this."

       -ABC News' Lindsey Krill and Jennifer Watts contributed to this report.