document: Built in the 1970s, the 21 and 23-storey Aston University blocks had been accommodation for generations of students living on campus.
  Billy Young, from Demolition Ltd, said it was a complex operation because of the site and need to divert services.
  The demolition is part of a ??300m regeneration of the campus. Students were able to watch the event.
  He said: "The logistics of working on a live campus, live services - there were a lot of services that had to be diverted in and around the site before the implosion could take place.
  "We also had complications of a Victorian water main and gas mains and adjacent footpath that had to monitored on the day in case of any vibration damage."
  The Aston Student Village and new research centres will be completed by 2014.
  The first phase of the ??215m village project was finished last year which provided more than 1,300  bedrooms for students.
  The next stage of the scheme will provide another 1,050 rooms by next yea and will start now Dalton and Lawrence Towers have been brought down.
summary: Two university tower blocks have been demolished in a controlled explosion in central Birmingham.