A structure inside the Jakarta Stock Exchange tower collapsed today, injuring several people and forcing a chaotic evacuation. TV footages showed the lobby strewn with debris and people being helped out of the building while others lay on the grass or steps outside the tower. <br/><br/>It was not immediately clear what part of the building collapsed but the structure may have been a balcony or walkway based on TV images. Jakarta police spokesman Argo Yuwono said hundreds of students were visiting the stock exchange at the time. <br/><br/>There was no immediate explanation for the collapse. Metro TV said 15 ambulances were deployed to take victims to hospitals.