May 31 (Reuters) - The following are the top stories in the Wall Street Journal. Reuters has not verified these stories and does not vouch for their accuracy.

- Martin Senn, former chief executive of Zurich Insurance Group AG who stepped aside in December, has killed himself, the company said - the second suicide by a one-time top manager at the company in the past few years. (http://on.wsj.com/1O0G7oU)

- Iraqi special forces advanced to the edge of Fallujah on Monday but struggled to enter the city, where Iraqi and U.S. officials said Islamic State extremists were amassing civilians to serve as human shields. (http://on.wsj.com/1O0GdwW)

- Jazz Pharmaceuticals PLC is nearing a deal to buy Celator Pharmaceuticals Inc for about $1.5 billion, a large premium for a company with a promising leukemia drug but no revenue. (http://on.wsj.com/1O0Ghww)

- Two unions representing more than 36,000 Verizon workers won concessions from the carrier in a new four-year contract, helping to end a nearly seven-week labor strike. (http://on.wsj.com/1O0Gvnh)

(Compiled by Abinaya Vijayaraghavan in Bengaluru)