context: Early morning, Ty Hackett (Columbus Short) is getting ready for work. He wakes up his younger brother, Jimmy (Andre Kinney), and tells him to get ready for high school. Ty is a war hero, having earned the Silver Star in Iraq. Both his parents recently died and left him with the mortgage and Jimmy to look out for. Ty is picked up by Mike Cochrane (Matt Dillon), and they carpool to work at the Eagle Shield Armored Truck Co.At work, the security team meets for the morning briefing with Chief Ashcroft (Fred Ward). They get their assignments and Ty, Mike and Baines (Laurence Fishburne) go to a bank. They pick up the money and on the way back, Baines notices a black van following them. The truck stalls in a small underpass and they have no radio reception due to the location. Mike says he smells sugar and they worry that someone has sabotaged the truck as they desperately try to restart it. Ty is in the back with the money and sees a black van speeding towards them. The van stops, and masked men get out and attach an explosive device on the back of the armored truck. Ty is scared and braces for the explosion, which turns out to be just a bottle rocket. Mike and Baines laugh hysterically, and the men remove their hoods: it was Tys final test and now he is a full-fledged guard. The guys go out for drinks to celebrate.While drinking, they tell him a story about a hijacked armored truck in Abilene years ago where they got away with $4 million; the thieves were never caught and the money was never found.At work, Ty asks Ashcroft for extra shifts; he is in jeopardy of losing his house to the bank. Mike tells him that theyll figure out something, and that he is like family to him.While they are driving, Mike talks again about the Abilene heist, and tells him that he thinks it was a fake-that the guards took the money.They go for dinner at a hot dog stand, and local Sheriff Eckehart (Milo Ventimiglia) is there. Mike tells Ty that tomorrow they will probably be carrying $42 million in their truck. Ty asks if he thinks they might get jacked and Mike says yes. He tells him that the other four guys on the team are in, and they are going to jack the entire $42 mil, and pretend they were hijacked. Ty tells him hes crazy and wants no part of it. Mike tells him to sleep on it, and if hes in, to be at the bus stop in the morning. Ty is in shock at the idea of robbing the company and refuses a ride, and runs the whole way home.Once home, Ty is met by a lady who works for Child Protective Services. Jimmy has skipped more school than hes attended, and she is thinking of removing Jimmy from Tys care and putting him in foster care, especially when she hears they may lose the house.The next morning, Mike is at the bus stop and waits for Ty to show up, but he never does. In the locker room, no one speaks, but by showing up without Ty, they know he is out and they are worried about their plan. Suddenly, Ty shows up, and they smile. At their lockers, Ty makes Mike promise that no one will get hurt, because he cant go to jail and leave Jimmy, and that he cant have any more blood on his hands. Mike promises.The two trucks go the bank, and each has three agents: one team is Mike, Baines and Ty, and the other truck has Quinn (Jean Reno), Palmer (Amaury Nolasco), and Dobbs (Skeet Ulrich). The money is divided into the two trucks, while be guarded by heavily armed guards. The two trucks drive off and radio in at the checkpoint. Ashcroft OKs the position and expects them in 51 minutes.The trucks pull into an abandoned steel mill, which is full of old buildings and smokestacks. It is next to electrical transformers and they lose radio contact due to interference. Inside, they park the trucks and unload the money. They put it in duffel bags and then down deep in one of the smokestacks. They see someone outside move past a window, and chase him. It is an old homeless man, and when they chase him up the catwalk, he is shoved and falls. Ty rushes down, and sees he isnt dead, and drags him towards a truck. Baines shoots the homeless man in the back. Ty is furious, and said he could have survived if hed gotten medical care. Mike is angry at Baines for shooting him, but realizes they had no other choice. Ty runs to one of the trucks, and locks himself in. Mike tries to talk Ty into opening the truck doors, but Ty wont and then drives off. Mike takes the other truck and follows him in a high-speed chase through the steel mill. Mike finally gets ahead and rams Tys truck. The trucks crash. Ty turns on the siren, and Mike fumbles with the hood and then pulls out the fuse, turning off the siren.Meanwhile back at the hot dog stand, Sheriff Eckehart hears a faint siren, and goes to investigate.Mike and the gang realize Ty isnt coming out, and they only have 40 minutes left, so they plan to pound the bolts on the hinges of the armored trucks back doors, until they release, and break into Tys truck. They will kill Ty and tell the cops he died a hero trying to stop the hijacking. They begin hitting the thick steel hinges, and they hardly budge. The guys take turns swinging the hammer at the hinges, switching off when they tire.Ty whispers to Dobbs while the others are hitting the hinge, and gets him to help him. Dobbs tries to get the fuse from the other truck to give to Ty, and Baines catches him. He beats up Dobbs and then pours gas all over the engine. Before he lights it, Mike stops him and tells him it is a stupid idea, because if the truck burns, so does the money. Palmer walks with Dobbs and they talk, and Dobbs thinks all is ok, and then Palmer stabs him.Sheriff Eckehart drives around the lot, and loses radio contact. Before he can enter the building and catch them, Mike comes out, and tells him he is the security guard for the property and also the handyman.Ty has an idea, and tries to hook up the siren with parts from other equipment in the truck, so the sheriff will hear it. As the sheriff is about to leave, Tys siren sounds, and Baines shoots the sheriff with his shotgun. Mike drags him inside, and he is bleeding from a shot to the stomach, but alive. While they are distracted with the sheriff and arguing with each other, Ty sneaks out of the truck and lights the stash of stolen money on fire with a flare, and runs back. The guys run to the money, and Ty takes the sheriff to the armored truck and locks him in with himself. He tries to clean the wound and stop the bleeding. Without saying anything, Quinn drives the other truck away, with some sort of plan.While Quinn is gone, Ty has an idea: he sticks dollar bills all over the windows so they cant see in, and then while they are banging in the hinges, he pries the floor panel of the truck open, and sneaks out with the sheriffs radio, to go to the roof and try to get a signal. He does and gets a call out, and turns to find Palmer with a gun on him. Palmer is distressed, and cant justify how wrong things have gone, and instead of shooting Ty, he jumps off the roof, killing himself. Ty sneaks safely back in the truck, and tells the sheriff that help is on the way.Quinn returns with Jimmy, who he has kidnapped. Mike threatens to shoot Jimmy in the head, and so Ty opens the truck doors. They grab Ty and beat him a bit. As Quinn and Baines open the box with all the money in Tys truck, it explodes as he set a trap with flares inside. There is a huge explosion, and the two men are flung from the truck. Mike is, too, but since he wasnt in the truck, he lives. Ty makes Jimmy hide, and then runs. He heads for the sheriffs car, and while trying to start it, is rammed by Mike driving the other armored truck. Ty escapes, and starts running on foot with Mike chasing him in the truck. Ty sees a drop in the road and jumps down, and Mike drives the truck right down into the hole, crashing the truck. Ty walks over, and we see Mike, thrown from the truck take a few breaths, then die. Ty walks away.At the hospital, Ty sees the sheriff through his window, and it appears that he will be OK. Ashcroft walks out, and tells Ty that Sheriff Eckehart explained all that Ty did to save him, and he mentions there might even be a reward. He smiles and leaves. Jimmy exits the ER, with a few bandages on and the two brothers go home.
question: Who set off the trucks alarm?
answer: Ty